Citation Nr: 1622423 Decision Date: 06/03/16 Archive Date: 06/13/16 DOCKET NO. 06-05 255 ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Sioux Falls, South Dakota THE ISSUES 1. Entitlement to service connection for irritable bowel syndrome (IBS) as secondary to chronic use of non-steroidal anti-inflammatory (NSAID) medication for treatment of multiple service-connected disabilities. 2. Entitlement to a total disability rating based on individual unemployability (TDIU) due to service-connected disabilities from January 15, 2002 to October 30, 2006. 3. Entitlement to special monthly compensation by reason of being housebound. 4. Entitlement to a separate 10 percent rating for right leg sciatica associated with degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine from January 15, 2002. 5. Entitlement to a separate 10 percent rating for left leg sciatica associated with degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine from January 15, 2002. REPRESENTATION Veteran represented by: John S. Berry, Jr., Attorney WITNESS AT HEARINGS ON APPEAL The Veteran ATTORNEY FOR THE BOARD Paul S. Rubin, Counsel INTRODUCTION The Veteran had active duty service in the U.S. Army from June 1979 to September 1979 and from November 1980 to June 1993. The irritable bowel syndrome issue comes to the Board of Veterans' Appeals (Board) on appeal from a July 2005 rating decision issued by the Department of Veterans Affairs (VA) Regional Office (RO) in St. Louis, Missouri. Jurisdiction of case has since been transferred to the RO in Sioux Falls, South Dakota. That office forwarded his appeal to the Board. The right and left leg sciatica issues come to the Board on appeal from a February 2014 rating decision issued by the RO in Sioux Falls, South Dakota. The TDIU and special monthly compensation issues come to the Board on appeal from an August 2014 rating decision issued by the RO in Sioux Falls, South Dakota. This appeal was processed using Virtual VA and the Veterans Benefits Management System (VBMS). Accordingly, any future consideration of this Veteran's case should take into consideration the existence of this electronic record. In January 2004, March 2007, and June 2008, the Veteran testified at hearings before Decision Review Officers (DRO hearings). In April 2009, the Veteran presented testimony at a Travel Board hearing before the undersigned Veterans Law Judge. Transcripts of both hearings are associated with the VBMS folder. In September 2009, the Board remanded the appeal for further development. In September 2011, the Board denied the issues of service connection for irritable bowel syndrome, an increased rating greater than 40 percent for degenerative disc disease of the thoracolumbar spine, and increased ratings greater than 10 percent for right and left leg sciatica. The Veteran appealed the Board's September 2011 decision to the United States Court of Appeals for Veterans Claims (Court). In a January 2013 Order, the Court partially vacated and remanded the Board's decision as to the issues of service connection for irritable bowel syndrome and an increased rating greater than 40 percent for degenerative disc disease of the thoracolumbar spine, for proceedings consistent with a Joint Motion for Remand (Joint Motion). In November 2013, upon return from the Court, the Board once again remanded the issues of service connection for irritable bowel syndrome and an increased rating greater than 40 percent for degenerative disc disease of the thoracolumbar spine, for further development. After completing this development, the RO in a February 2014 rating decision granted the Veteran an increased 60 percent rating for degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine, effective January 15, 2002. The RO also consolidated the previous 10 percent evaluations for right and left leg sciatica into the 60 percent rating for the thoracolumbar spine under Diagnostic Code 5293 (the version in effect prior to September 23, 2002). In the February 2014 rating decision, the RO also determined that the grant of a 60 percent rating for the Veteran's degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine was a full grant of the benefits sought on appeal for this issue. In this regard, a veteran is presumed to be seeking the highest possible rating, unless he expressly indicates otherwise. AB v. Brown, 6 Vet. App. 35, 39 (1993). Here, the veteran expressly indicated on several occasions that he was seeking a 60 percent rating for the thoracolumbar spine. See August 2004 VA Form 9; March 2007 and June 2008 DRO hearings; and April 2008 Veteran's statement. Moreover, the Veteran's attorney in March 2014, October 2014, and December 2015 letters, did not list the issue of an increased rating for the thoracolumbar spine as being on appeal any longer. Therefore, the Board concludes the issue of an increased rating for degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine is no longer on appeal at this juncture. However, despite the fact that the Veteran has been awarded a 60 percent rating for degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine with consideration of sciatic neuropathy, the Board will still consider whether the Veteran is entitled to separate, additional 10 percent ratings for right and left leg sciatica from January 15, 2002. In fact, the issues of entitlement to separate 10 percent ratings for right and left leg sciatica were specifically appealed by the Veteran from the February 2014 rating decision on appeal. See Bierman v. Brown, 6 Vet. App. 125, 129-132 (1994) (holding that manifestations of neurological symptomatology of a lower extremity which are distinct and separate from low back symptoms (that is, neither duplicative nor overlapping) could be rated under a diagnostic code different from Diagnostic Code 5293 without violating the VA anti-pyramiding regulation of 38 C.F.R. § 4.14). The issues of separate 10 percent ratings for right and left leg sciatica and entitlement to a TDIU from January 15, 2002 to October 30, 2006 are REMANDED to the Agency of Original Jurisdiction (AOJ). VA will notify the Veteran if further action is required. FINDINGS OF FACT 1. There is an approximate balance of favorable and unfavorable evidence as to whether the Veteran has irritable bowel syndrome proximately due to or the result of pain medications from his service-connected hiatal hernia, thoracolumbar spine, cervical spine, migraine headache, bilateral hip, bilateral shoulder, and bilateral knee disabilities. 2. With regard to housebound benefits, the Veteran does not have a service-connected disability rated as 100 percent disabling. However, the Veteran's TDIU rating due to a single disability (thoracolumbar spine degenerative disc disease and intervertebral disc disease with sciatic neuropathy) does meet this requirement under recent VA case law. Moreover, the Veteran has additional service-connected disabilities independently ratable at 60 percent or more when combined, separate and distinct from the thoracolumbar spine TDIU disability, and involving different anatomical segments or bodily systems. This meets the statutory criteria for housebound benefits. CONCLUSIONS OF LAW 1. Resolving all reasonable doubt in his favor, the Veteran has irritable bowel syndrome secondary to medication from his service-connected disabilities. 38 U.S.C.A. §§ 1110, 5103, 5103A, 5107 (West 2014); 38 C.F.R. §§ 3.102, 3.159, 3.310 (in effect prior to October 10, 2006). 2. Effective October 30, 2006, the criteria are met for entitlement to special monthly compensation benefits by reason of being permanently housebound. 38 U.S.C.A. §§ 1114(s), 5103, 5103A, 5107 (West 2014); 38 C.F.R. §§ 3.102, 3.159, 3.350(i), 4.16(a) (2015). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS I. VA's Duty to Notify and Assist The Veterans Claims Assistance Act of 2000 (VCAA), in part, describes VA's duties to notify and assist claimants in substantiating a claim for VA benefits. 38 U.S.C.A. §§ 5100, 5102, 5103, 5103A, 5106, 5107, 5126 (West 2014); Honoring America's Veterans and Caring for Camp Lejeune Families Act of 2012, Pub. L. No. 112-154, §§ 504, 505, 126 Stat. 1165, 1191-93; 38 C.F.R. §§ 3.102, 3.156(a), 3.159, 3.326(a) (2015). The VCAA applies to the instant secondary service connection and special monthly compensation claims. However, the Veteran was provided adequate VCAA notice for these issues in April 2005, July 2008, and May 2014. Moreover, if any defect in VCAA notice or assistance is found, such defect is not prejudicial to the Veteran, given the completely favorable disposition of the secondary service connection and special monthly compensation issues on appeal. Bernard v. Brown, 4 Vet. App. 384, 392-94 (1993). II. Secondary Service Connection for IBS Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active military, naval, or air service. 38 U.S.C.A. §§ 1110, 1131; 38 C.F.R. § 3.303(a). A disability also can be service connected if it is proximately due to or the result of a service-connected disease or injury. 38 C.F.R. § 3.310(a). Secondary service connection may also be established when there is aggravation of a veteran's non-service-connected condition that is proximately due to or the result of a service-connected condition. Allen v. Brown, 7 Vet. App. 439, 448 (1995); Tobin v. Derwinski, 2 Vet. App. 34, 39 (1991). The Board is aware of the change in 38 C.F.R. § 3.310, effective October 10, 2006. See 71 Fed. Reg. 52,744-52,747 (September 7, 2006). The amendment sets a standard by which a claim based on aggravation of a non-service-connected disability by a service-connected one is judged. Although VA has indicated that the purpose of the regulation was merely to apply the Court's ruling in Allen v. Brown, 7 Vet. App. 439, 446-449 (1995), it was made clear in the comments to the regulation that the changes were intended to place a burden on the claimant to establish a pre-aggravation baseline level of disability for the nonservice-connected disability before an award of service connection may be made. See 71 Fed. Reg. 52,745 (Sept. 7, 2006). This had not been VA's practice, which suggests that the recent change amounts to a substantive change. Clearly, the new regulation is more restrictive and the Board shall not give impermissibly retroactive effect to the new regulation in this case. Since the Veteran's claim for service connection for irritable bowel syndrome was filed in March 2005, the Board will consider the previous version of 38 C.F.R. § 3.310 in effect before the change, which clearly favors the Veteran. In short, in order to establish entitlement to service connection on a secondary basis, there must be (1) evidence of a current disability; (2) evidence of a service-connected disability; and (3) probative evidence establishing a nexus (i.e., link) between the service-connected disability and the current disability. Wallin v. West, 11 Vet. App. 509, 512 (1998). VA is to give "due consideration" to "all pertinent medical and lay evidence" in evaluating a claim for disability benefits. 38 U.S.C.A. § 1154(a) (West 2014). The Federal Circuit has held that medical evidence is not always or categorically required in every instance to establish a medical diagnosis or the required nexus in a service connection case. Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009). That is, lay evidence can also be competent and sufficient evidence of a diagnosis or to establish etiology if (1) the layperson is competent to identify the medical condition, (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional. Davidson, 581 F.3d at 1316. See also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). In short, when considering whether lay evidence is competent the Board must determine, on a case by case basis, whether the Veteran's particular disability is the type of disability for which lay evidence may be competent on the issues of diagnosis and medical causation. Kahana v. Shinseki, 24 Vet. App. 428, 438 (2011). For instance, a layperson is competent to identify such disorders as varicose veins, tinnitus, and flat feet. 38 C.F.R. § 3.159(a)(2); Barr v. Nicholson, 21 Vet. App. 303, 310 (2007); Charles v. Principi, 16 Vet. App. 370, 374 (2002); Falzone v. Brown, 8 Vet. App. 398, 405 (1995). In contrast, a layperson is not competent to identify medical conditions that require scientific, technical, or other specialized knowledge, such as in identifying bronchial asthma. 38 C.F.R. § 3.159(a)(1); Layno v. Brown, 6 Vet. App. 465, 469 (1994). The Board must assess the competence and credibility of lay statements. Barr, 21 Vet. App. at 308. In determining whether secondary service connection is warranted, the Board shall consider the benefit-of-the-doubt doctrine. 38 U.S.C.A. 5107(b); 38 C.F.R. § 3.102; Alemany v. Brown, 9 Vet. App. 518 (1996); Gilbert v. Derwinski, 1 Vet. App. 49 (1991). Upon review of the evidence of record, the Board finds that the Veteran is entitled to service connection for irritable bowel syndrome as secondary to medication from the Veteran's service-connected disabilities. The Veteran contends that he has irritable bowel syndrome or recurring diarrhea with lower intestinal distress as the result of taking non-steroidal anti-inflammatory (NSAID) medication his for service-connected orthopedic conditions and as the result of proton pump inhibitors (PPIs) prescribed for his service-connected hiatal hernia. The Veteran has submitted recent medical treatise studies presenting some evidence of a correlation between NSAIDs and PPIs with irritable bowel syndrome or frequent diarrhea. See March 2014 attorney letter. The Veteran is service-connected for hiatal hernia, thoracolumbar spine, cervical spine, migraine headache, bilateral hip, bilateral shoulder, and bilateral knee disabilities. The first and most fundamental requirement for any service-connection claim, on either a direct or secondary basis, is the existence of a current disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000). Here, VA examiners and VA physicians have assessed either irritable bowel syndrome or a history of alternating diarrhea and constipation for the Veteran. See VA examination dated in May 2007; VA primary care and nursing notes dated in July 2007, August 2007, December 2007, and March 2008; VA stomach examinations dated in May 2010 and January 2014; and VA treatment records dated from 2009 to 2013. The Veteran also credibly described his frequent symptoms of constipation and diarrhea during DRO hearing testimony in March 2007 and June 2008, and Travel Board hearing testimony in April 2009. Thus, the evidence clearly reveals irritable bowel syndrome or similar lower intestinal disorder. With regard to secondary service connection for irritable bowel syndrome, the evidence in the claims folder contains favorable and unfavorable medical opinions, mixed opinions, and medical treatise evidence. In analyzing the evidence, the Board must determine, as a question of fact, both the weight and credibility of the evidence. Equal weight is not accorded to each piece of evidence contained in a record; every item does not have the same probative value. The Board must account for the evidence which it finds to be persuasive or unpersuasive, analyze the credibility and probative value of all material evidence submitted by and on behalf of a claimant, and provide the reasons for its rejection of any such evidence. See Struck v. Brown, 9 Vet. App. 145, 152 (1996); Caluza v. Brown, 7 Vet. App. 498, 506 (1995); Gabrielson v. Brown, 7 Vet. App. 36, 40 (1994); Abernathy v. Principi, 3 Vet. App. 461, 465 (1992); Simon v. Derwinski, 2 Vet. App. 621, 622 (1992); Hatlestad v. Derwinski, 1 Vet. App. 164, 169 (1991). With regard to favorable evidence, there is some probative medical evidence of record that demonstrates that the Veteran's irritable bowel syndrome is proximately due to or the result of medication from his service-connected disabilities. 38 C.F.R. § 3.310(a); Velez v. West, 11 Vet. App. 148, 158 (1998). Specifically, VA treatment records dated from 2003 to 2013 confirm that the Veteran has been prescribed and taken numerous NSAIDs and PPIs such as Codeine, Indocin, Naproxen, Valium, Flexeril, Motrin, Percocet, Darvocet, Tylenol, aspirin, and omeprazole, among others. Moreover, a February 2004 VA examiner observed that the Veteran has problems with his upper and lower stomach and he attributes this to his chronic NSAID use for his orthopedic pain. In particular, he has heartburn, and is constipated approximately twice a week and has diarrhea approximately twice a week. The VA examiner opined it is "more than likely" that his heartburn and stomach discomfort is related to overuse of NSAIDs and hiatal hernia. The VA examiner also opined that on a more probable basis his stomach problems are due to chronic NSAID use. Notably, the VA examiner did not distinguish between the Veteran's upper and lower stomach disorders when relating them to his chronic NSAID use. Based on this VA opinion, in a May 2004 rating decision, the RO awarded secondary service connection for hiatal hernia caused by medications for the Veteran's service-connected thoracolumbar and cervical spine disabilities. (Subsequently, the Veteran filed his service connection claim for irritable bowel syndrome as well in March 2005). With regard to favorable evidence, in March 2014 the Veteran submitted a medical treatise research study on PPIs and NSAID exposure in irritable bowel syndrome cases. The study concluded that "one should be aware that prescribing PPIs for upper GI complaints or NSAIDs for pain relief may potentially trigger mechanisms resulting in symptom generation representative for IBS." However, the study also cautioned that "[a]s case-control studies generally do not allow interpretation of a cause-effect relationship, further research should include prospective evaluation of PPI users and NSAIDs users monitoring the development of IBS-symptoms in relation to drug exposure to ascertain whether this increased exposure to PPIs' and NSAIDs should be considered as legitimate etiological factors in IBS." Although the Court has held that, in general, information contained within medical articles and treatise evidence is too abstract to prove the nexus element of a service-connection claim, the Court has also held that treatises "can provide important support when combined with an opinion of a medical professional." Sacks v. West, 11 Vet. App. 314, 316-17 (1998). Furthermore, a medical article or treatise, standing alone, may provide sufficient evidence of a causal connection when it "discusses generic relationships with a degree of certainty" so that the causal connection is "based upon objective facts rather than on an unsubstantiated lay medical opinion." Id. at 317. Moreover, the Board emphasizes the Court also held that VA, under the benefit of the doubt rule contained in 38 U.S.C. § 5107(b), must consider and discuss, rather than dismiss, potentially favorable medical literature of record, even if the medical principle contained in the literature has not reached a level of scientific consensus or is "generally accepted" in the medical community. VA may consider the extent to which a scientific theory is accepted in the scientific community when evaluating the evidence of record, but cannot demand a level of acceptance in the scientific community greater than the level of proof required by the benefit of the doubt rule. Wise v. Shinseki, 26 Vet. App. 517, 531-32 (2014). In short, in the present case, the medical treatise research article submitted by the Veteran in March 2014 provides some limited evidence of the potential for a cause and effect relationship between PPIs and NSAIDs with irritable bowel syndrome. With regard to the unfavorable evidence regarding secondary service connection for irritable bowel syndrome, a January 2014 VA stomach examiner concluded "[i]t is less likely as not that the veteran's IBS is proximately due to multiple service connected joint and headache disabilities, to include treatment of such with NSAID medications. It is also less likely as not that the condition of IBS was aggravated by the veteran's multiple service connected joint and headache disorders and treatment of such with analgesic or NSAID medications. The VA examiner reasoned that although occasional use of NSAIDs may be associated with symptoms of GERD, dyspepsia, or stomach upset, it is not a well-known cause of changes in the intestinal tract, or IBS with persistent severe abdominal pain, cramping or diarrhea/constipation. The VA examiner also added there is no evidence in his medical records that specific treatment of his headaches and joint complaints resulted in worsening of an IBS condition. The VA examiner also questioned how frequently the Veteran was actually taking NSAIDs. (The Veteran's attorney in a March 2014 attorney letter countered that the Veteran should not be punished because he has attempted to decrease his pain management in more recent times in order to lessen the effects of his use of NSAIDs on his overall health. The Veteran's attorney also cited a medical treatise link indicating that one of the Veteran's prescribed NSAIDs - the drug etodolac, lists diarrhea and constipation as two of its most common side effects). With regard to the unfavorable evidence regarding secondary service connection for irritable bowel syndrome, in an April 2014 VA addendum opinion, the VA stomach examiner again assessed that it is "less likely as not" that the Veteran's complaint of irritable bowel syndrome diagnosis is due to or aggravated by use of non-steroidal anti-inflammatory medications or any other medication (including PPI's) for service connected disabilities. The Veteran's opinion for causation of his symptoms or worsening of irritable bowel syndrome symptoms is not substantiated by numerous medical visits. In addition, the VA examiner added the issue of causation of irritable bowel syndrome by certain medications is also at issue. The VA examiner also noted a specific diagnosis of irritable bowel syndrome has not been documented in his medical chart, either during or after service (as discussed above, the Board finds this is not the case). With regard to the medical treatise evidence submitted by the Veteran, the VA examiner emphasized further prospective studies are needed to monitor development of irritable bowel syndrome in relation to drug exposure. Finally, the VA examiner stated that the Veteran's medical records primarily refer to the veteran having GI discomfort as a result of use of various NSAIDs, which constitutes "exacerbations" rather than an etiological cause for irritable bowel syndrome or an actual aggravation beyond its natural progression. These symptoms then subside after the offending medication is discontinued. Based on the evidence of record contained in VA treatment notes dated from 2003 to 2013, the Board has determined this particular finding by the VA examiner is questionable as well. As currently codified, VA law defines the "benefit of the doubt" doctrine as: When, after consideration of all evidence and material of record in this case before the Department with respect to benefits under laws administered by the Secretary, there is an approximate balance of positive and negative evidence regarding the merits of an issue material to the determination in the matter, the benefit of the doubt in resolving each such issue shall be given to the claimant. 38 U.S.C.A. § 5107(b). See also 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). Here, there is an approximate balance of the positive and negative evidence as to secondary service connection for irritable bowel syndrome. Certain elements of both the positive and negative opinions in this case, as well as the medical treatise evidence, are probative. All of the medical opinions have their respective flaws as well. But there is no apparent basis for wholly rejecting the favorable opinions of record. In light of the contrasting, yet equally probative medical opinions in the present case, in such situations, the benefit of the doubt is resolved in the Veteran's favor. Accordingly, secondary service connection for irritable bowel syndrome is warranted. 38 U.S.C.A. § 5107(b); 38 C.F.R. § 3.102. The Board emphasizes that it is granting secondary service connection for irritable bowel syndrome on the basis that it is the direct result of NSAIDs and PPIs for his service-connected disabilities, as opposed to aggravation. II. Special Monthly Compensation (Housebound Benefits) Upon review of the evidence, special monthly compensation by reason of being permanently housebound is warranted, effective October 30, 2006. The Veteran is seeking special monthly compensation benefits based on being housebound as set forth under 38 U.S.C.A. § 1114(s). There is no indication in the record that the Veteran is seeking special monthly compensation benefits based on the need for regular aid and attendance at the higher rate as set forth under 38 U.S.C.A. § 1114(l). See December 2015 attorney letter. Special monthly compensation benefits by reason of being housebound are payable if the Veteran has a single permanent disability rated 100 percent disabling, and has either (1) additional service-connected disability or disabilities independently ratable at 60 percent or more, or (2) is "permanently housebound" by reason of service-connected disability or disabilities. 38 U.S.C.A. § 1114(s); 38 C.F.R. § 3.350(i). The disabilities independently ratable at 60 percent or more must be separate and distinct from the 100 percent service-connected disability and involving different anatomical segments or bodily systems. 38 C.F.R. § 3.350(i)(1). Housebound benefits are not available to a Veteran whose 100 percent disability rating is based on multiple disabilities, none of which is rated at 100 percent disabling. Guerra v. Shinseki, 642 F.3d 1046 (Fed. Cir. 2011). However, a total disability rating based on individual unemployability (TDIU) satisfies the total (100 percent) rating requirement if the TDIU evaluation was, or can be, predicated upon a single disability and there exists additional disability or disabilities independently ratable at 60 percent or more, for purposes of entitlement to special monthly compensation for a housebound rating. Bradley v. Peake, 22 Vet. App. 280, 293 (2008). In other words, a TDIU rating based on a single disability, but not multiple disabilities, is permitted to satisfy the statutory requirement of a total rating. Bradley, 22 Vet. App. at 293. Nonetheless, the TDIU rating based on a single disability that satisfies the total (100 percent) rating requirement must be separate and distinct from the additional disability or disabilities independently ratable at 60 percent or more for purposes of housebound benefits. Bradley, 22 Vet. App. at 293. In addition, the decision to treat multiple disabilities as one under 38 C.F.R. § 4.16(a) is specifically limited to TDIU ratings. That is, a TDIU rating based on multiple service-connected disabilities does not satisfy the criteria for one total disability in considering entitlement to housebound benefits under 38 U.S.C.A. § 1114(s). Bradley, 22 Vet. App. at 290-91. A "TDIU rating that is based on multiple disabilities cannot satisfy the section 1114(s) requirements of 'a service-connected disability' because that requirement must be met by a single disability." Buie v. Shinseki, 24 Vet. App. 242, 249-250 (2010). However, VA's duty to maximize benefits requires VA to assess all of a claimant's disabilities, regardless of the order in which they were service-connected, to determine whether any combination of disabilities establishes housebound benefits under 38 U.S.C. § 1114(s). Buie, 24 Vet. App. at 249-250. A veteran is permanently housebound when he is substantially confined to his house (ward or clinical areas, if institutionalized) or immediate premises as a direct result of his service-connected permanent disability or disabilities, and it is reasonably certain that the disability of disabilities and resultant confinement will continue throughout his or her lifetime. 38 U.S.C.A. § 1114(s); 38 C.F.R. § 3.350(i)(2). Review of the claims folder reveals that the Veteran currently has the following service-connected disabilities: a thoracolumbar spine disability, rated as 60 percent disabling; migraine headaches, rated as 50 percent disabling; a cervical strain, rated as 30 percent disabling; primary insomnia, rated as 30 percent disabling; a right hip disability, rated as 20 percent disabling; a left hip disability, rated as 20 percent disabling; a left shoulder disability, rated as 20 percent disabling; a right shoulder disability, rated as 20 percent disabling; a right knee disability, rated as 10 percent disabling; a left knee disability, rated as 10 percent disabling; tinnitus, rated as 10 percent disabling; hiatal hernia, rated as 10 percent disabling; and bilateral vitreous floaters, bilateral hearing loss, and hemorrhoids, each rated as 0 percent disabling. The combined service-connected disability rating with consideration of the bilateral factor is 100 percent from October 30, 2006. See 38 C.F.R. §§ 4.25 (combined ratings table); 4.26. Therefore, the percentage criteria for TDIU are clearly met. 38 C.F.R. § 4.16(a). The Veteran is in receipt of a TDIU rating since October 30, 2006. That is, in a June 2007 rating decision, the RO granted the Veteran a schedular TDIU rating under 38 C.F.R. § 4.16(a), as of that date. The TDIU rating was based on the fact that as of October 30, 2006, the Veteran met the schedular percentage requirements for TDIU (he had a 100 percent combined rating). He was also determined to be unable to secure or follow a substantially gainful occupation as a result of service-connected disabilities as of that date. See 38 C.F.R. § 4.16(a). The TDIU award, effective October 30, 2006, was based on the findings of a May 2007 VA examiner who indicated the Veteran could no longer work as a program technician as of November 2006 due to multiple service-connected disabilities - i.e, his hips, thoracolumbar spine, cervical spine, headaches, and primary insomnia (previously diagnosed as depression). With regard to housebound status, the threshold statutory requirement is that the Veteran must have a single permanent disability rated at a schedular 100 percent. 38 U.S.C.A. § 1114(s); 38 C.F.R. § 3.350(i). The Veteran does not have a single permanent disability rated at 100 percent, at any point during his appeal. His highest rated disability is his thoracolumbar spine disability, which is rated as 60 percent disabling. Absent a single disability rated as 100 percent disabling, the Veteran normally would not meet the threshold legal criteria for entitlement to special monthly compensation under 38 U.S.C.A. § 1114(s) and 38 C.F.R. § 3.350(i). However, in the aforementioned June 2007 rating decision, the Veteran was awarded a TDIU rating, effective from October 30, 2006. Nevertheless, when the RO awarded the TDIU rating, the RO predicated the TDIU award on the combination of the effects of his service-connected bilateral hip, thoracolumbar spine, cervical spine, headaches, and primary insomnia (previously diagnosed as depression) disabilities. See June 2007 rating decision. The RO did not determine that the effects of a single service-connected disability, standing alone, were sufficient to award the TDIU rating due to unemployability. Again, only a TDIU rating based on a single disability, but not multiple disabilities, is permitted to satisfy the statutory requirement of a total rating for housebound purposes. Bradley, 22 Vet. App. at 290-91. In short, the TDIU award in this case was based on multiple disabilities, which would rule out housebound benefits for the Veteran. The question is whether the Board agrees with the RO's assessment, or in the alternative whether the evidence of record shows that a single disability could have formed the basis for the TDIU award. In this regard, VA's duty to maximize benefits requires VA to assess all of a claimant's disabilities, regardless of the order in which they were service-connected, to determine whether any combination of disabilities establishes housebound benefits under 38 U.S.C. § 1114(s). Buie, 24 Vet. App. at 249-250. The Board must determine whether in the present case, a TDIU rating based on a single disability could satisfy the statutory requirement of a total rating for purposes of entitlement to special monthly compensation by reason of being housebound. Bradley, 22 Vet. App. at 293. In his November 2006 TDIU application, the Veteran stated that he last worked full-time on November 9, 2006. He listed his thoracolumbar spine, hips, and psychiatric problems as causes. However, at an earlier January 2006 VA spine and peripheral nerves examinations, the Veteran reported severe, constant pain from his thoracolumbar spine and bilateral leg sciatica, making it difficult to work in his job as a Veteran's Service Representative (VSR) for Douglas County. He was unable to walk more than a few yards, without using a cane. He was observed to have an antalgic gait, and waddled. The January 2006 VA examiner opined the Veteran's thoracolumbar spine and lower extremity sciatica (both considered as one disability for the 60 percent rating under Diagnostic Code 5293) had "significant effects" on the Veteran's ability to work. Specifically, his service-connected degenerative disc disease caused decreased mobility, problems with lifting and carrying, difficulty reaching, lack of stamina, decreased strength in the lower extremities, weakness and fatigue, fecal incontinence, and pain. The Veteran had specific job accommodations to include liberal usage of vacation time and liberal application of duty limitations - to avoid filing, stooping, sitting, and standing activities. Moreover, a latter February 2014 VA spine examination report on Virtual VA noted the Veteran's thoracolumbar spine, alone, impacts his ability to work. Due to the Veteran's back pain, he has difficulty with standing, sitting, and balance. The Veteran would only be able to do work consisting of brief periods of sitting and standing. He could not work in a job involving lifting, bending, or distance walking. The Veteran ended up leaving his job at the VSR in early November 2006, and has not worked ever since. In light of the above evidence, the Board finds that the Veteran's TDIU award, effective from October 30, 2006, could have been based on the effects of a single disability alone - specifically - the Veteran's service-connected thoracolumbar spine with sciatic neuropathy (rated as one disability under Diagnostic Code 5293). Thus, the TDIU award, effective October 30, 2006, could have been based on one single disability, which rendered the Veteran unable to secure or follow a substantially gainful occupation. See 38 C.F.R. § 4.16(a). Although the thoracolumbar spine disability was rated as only 60 percent disabling by the RO and was not rated as 100 percent disabling, for purposes of special monthly compensation for housebound benefits, the thoracolumbar spine disability satisfied the requirement of a "service-connected disability rated as total" based on the award of a TDIU rating. See Bradley and Buie, supra. See also 38 U.S.C.A. § 1114(s); 38 C.F.R. § 3.350(i). Therefore, this threshold housebound benefits requirement is met. Finally, as to the remaining statutory housebound requirement, the Veteran also has additional service-connected disabilities independently ratable at 60 percent or more when combined. 38 U.S.C.A. § 1114(s); 38 C.F.R. § 3.350(i). Moreover, in the present case, the disabilities independently ratable at 60 percent or more are separate and distinct from the TDIU thoracolumbar spine disability and involve different anatomical segments or bodily systems. 38 C.F.R. § 3.350(i)(1). Specifically, as of October 30, 2006, the Veteran has the following other service-connected disabilities: migraine headaches, rated as 50 percent disabling; primary insomnia, rated as 30 percent disabling; tinnitus, rated as 10 percent disabling; and hiatal hernia, rated as 10 percent disabling. These additional disabilities would combine to a 70 percent rating from October 30, 2006. See 38 C.F.R. §§ 4.25 (combined ratings table). Therefore, these additional service-connected disabilities are independently ratable at 60 percent or more when combined, and they are separate and distinct from the single thoracolumbar spine disability upon which the TDIU is based, and involve different anatomical segments or bodily systems. 38 C.F.R. § 3.350(i)(1). Therefore, resolving any doubt in the Veteran's favor, the Board finds the evidence of record supports special monthly compensation by reason of being permanently housebound, effective October 30, 2006. See 38 U.S.C.A. § 5107(b). ORDER Subject to the provisions governing the award of monetary benefits, service connection for irritable bowel syndrome as secondary to chronic use of medication for treatment of multiple service-connected disabilities is granted. Subject to the provisions governing the award of monetary benefits, entitlement to special monthly compensation by reason of being housebound is granted, effective October 30, 2006. REMAND A remand by the Board confers on the claimant, as a matter of law, the right to compliance with the remand orders. Stegall v. West, 11 Vet. App. 268, 271 (1998). Failure of the Board to ensure compliance with remand instructions constitutes error and warrants the vacating of a subsequent Board decision. Id. The Court has clarified that only substantial compliance, and not strict compliance, with the terms of an opinion request are required. D'Aries v. Peake, 22 Vet. App. 97 (2008). In the present case, the AOJ did not substantially comply with all of the development requested in the Board's earlier November 2013 remand. That is, first, the AOJ must obtain a VA addendum opinion from the same VA examiner who performed the February 2014 VA spine examination (on Virtual VA). This VA examiner provided a VA examination and opinion in February 2014, but it is not fully adequate. Specifically, the February 2014 VA examiner failed to directly answer a question posed by the Board. The VA examiner failed to answer whether the Veteran's sciatica of the right and left legs exhibits symptomatology separate and apart from the neurological symptomatology attributable to the Veteran's service-connected thoracolumbar spine degenerative disc disease. (The purpose of this question is to help determine whether there are any manifestations of neurological symptomatology of the Veteran's right and left legs that are distinct from the neurological symptomatology caused by his low back (that is, neither duplicative or overlapping), so that they could potentially be rated under a Diagnostic Code different from Diagnostic Code 5293 without violating the VA anti-pyramiding regulation - 38 C.F.R. § 4.14). Therefore, the claims folder will be returned to the February 2014 VA examiner for an addendum opinion. If the same VA spine examiner is not available, another qualified VA clinician will provide the addendum opinion. In this regard, prior to January 15, 2002, the Veteran was receiving separate 10 percent ratings for right and left leg sciatica associated with the Veteran's thoracolumbar spine degenerative disc disease under 4.124a, Diagnostic Code 8520 (2002). However, the RO in the February 2014 rating decision on appeal granted the Veteran an increased 60 percent rating for degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine, effective from January 15, 2002. In doing so, the RO consolidated the previous 10 percent evaluations for right and left leg sciatica into the 60 percent rating for the thoracolumbar spine under Diagnostic Code 5293 (the version in effect prior to September 23, 2002). Prior to September 23, 2002, under Diagnostic Code 5293, the Board observes that intervertebral disc syndrome, with persistent symptoms compatible with sciatic neuropathy with characteristic pain and demonstrable muscle spasm, absent ankle jerk, or other neurological findings appropriate to the site of the diseased disc, with little intermittent relief, warrants a 60 percent evaluation. 38 C.F.R. § 4.71a (2002). In other words, the earlier Diagnostic Code the Veteran is rated under (5293) contemplates the symptoms of sciatic neuropathy. The Board emphasizes it is permissible to switch diagnostic codes to reflect more accurately a claimant's current symptoms. See Read v. Shinseki, 651 F. 3d 1296, 1302 (Fed. Cir. 2011) (holding that service connection for a disability is not severed when the diagnostic code associated with it is changed to determine more accurately the benefit to which a veteran may be entitled). Regardless, the Board is also mindful of the Court's holding that manifestations of neurological symptomatology of a lower extremity which are distinct and separate from low back symptoms (that is, neither duplicative nor overlapping) could be rated under a diagnostic code different from Diagnostic Code 5293 without violating the VA anti-pyramiding regulation of 38 C.F.R. § 4.14). Bierman v. Brown, 6 Vet. App. 125, 129-132 (1994). Second, in the decision above, the Board has granted secondary service connection for irritable bowel syndrome. As a result, this case must be returned to the AOJ for the assignment of a disability rating and effective date for that grant, before reconsidering whether the Veteran is entitled to a TDIU from January 15, 2002 to October 30, 2006. In addition, the TDIU claim on appeal is inextricably intertwined with the separate rating claim for right and left sciatica. For these reasons, the separate rating claims for right and left sciatica in the present case must be resolved prior to resolution of the claim for TDIU. See Harris v. Derwinski, 1 Vet. App. 180, 183 (1991) (noting that the prohibition against the adjudication of claims that are inextricably intertwined is based upon the recognition that claims related to each other should not be subject to piecemeal decision-making or appellate litigation). Accordingly, a remand is required for the AOJ to adjudicate the inextricably intertwined claims. Third, as the appeal is already being remanded for other reasons, the Board sees the Veteran's VA treatment records on file from the Sioux Falls, South Dakota and Omaha, Nebraska VA healthcare systems date to November 2013. If the Veteran has since received additional relevant VA treatment, these records should be obtained. VA's duty to assist includes obtaining records of relevant VA medical treatment. 38 U.S.C.A. § 5103A(c)(2); 38 C.F.R. § 3.159(c)(2), (c)(3). See also Bell v. Derwinski, 2 Vet. App. 611 (1992) (VA is charged with constructive, if not actual, knowledge of evidence generated by VA). Accordingly, the case is REMANDED for the following action: 1. The AOJ should obtain the following VA treatment records and associate them with the claims file: (A) VA treatment records from the Sioux Falls, South Dakota VA healthcare system dated from November 2013 to the present. (B) VA treatment records from the Omaha, Nebraska VA healthcare system dated from November 2013 to the present. All attempts to secure these records, and any response received, must be documented in the claims file. If no VA treatment records are available, a response to that effect is required and should be documented in the file. 2. After securing the above records, the AOJ should secure a VA addendum opinion from the February 2014 VA spine examiner. If this VA examiner is no longer available, another qualified VA clinician must provide the addendum opinion. Only if deemed necessary by the VA examiner is an examination necessary. The entire claims file should be made available to and be reviewed by the examiner, and it should be confirmed that such records were available for review. An explanation for all opinions expressed must be provided. The February 2014 VA examiner previously did not answer all questions posed by the Board. Specifically, the VA examiner must answer whether the Veteran's sciatica of the right and left legs exhibits symptomatology separate and apart from the neurological symptomatology attributable to the Veteran's service-connected thoracolumbar spine degenerative disc disease. (The purpose of this question is to help determine whether there are any manifestations of neurological symptomatology of the Veteran's right and left legs that is distinct from the neurological symptomatology caused by his low back (that is, neither duplicative or overlapping). 3. After completing the above development, the AOJ should review the claims file and ensure that all of the foregoing development actions have been conducted and completed in full. See Stegall v. West, 11 Vet. App. 268, 271 (1998). 4. Thereafter, the AOJ should consider all of the evidence of record and readjudicate the remaining issues on appeal of entitlement to separate 10 percent ratings for right and left leg sciatica associated with degenerative disc disease and intervertebral disc syndrome of the thoracolumbar spine from January 15, 2002, and entitlement to a TDIU from January 15, 2002 to October 30, 2006. If the benefit sought is not granted, issue a Supplemental Statement of the Case (SSOC) and allow the Veteran and his attorney an opportunity to respond. The Veteran has the right to submit additional evidence and argument on the matter or matters the Board has remanded. Kutscherousky v. West, 12 Vet. App. 369 (1999). These claims must be afforded expeditious treatment. The law requires that all claims that are remanded by the Board of Veterans' Appeals or by the United States Court of Appeals for Veterans Claims for additional development or other appropriate action must be handled in an expeditious manner. See 38 U.S.C.A. §§ 5109B, 7112 (West 2014). ______________________________________________ DAVID L. WIGHT Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs