Citation Nr: 24006758 Decision Date: 02/07/24 Archive Date: 02/07/24 DOCKET NO. 20-05 663 DATE: February 7, 2024 ORDER Entitlement to service connection for gastroesophageal reflux disease (GERD), to include as due to a Gulf War illness, and to include as secondary to service-connected obstructive sleep apnea (OSA), is granted. REMANDED Entitlement to service connection for fatigue, to include as due to a Gulf War illness, and to include as secondary to GERD, is remanded. Entitlement to service connection for a gastrointestinal disorder, including irritable bowel syndrome (IBS), and to include as due to a Gulf War illness, is remanded. FINDING OF FACT Resolving all reasonable doubt in favor of the Veteran, the positive and negative evidence is in approximate balance that his currently diagnosed GERD was caused or aggravated by his service-connected OSA. CONCLUSION OF LAW The criteria for entitlement to service connection for GERD, to include as due to a Gulf War illness, and to include as secondary to service-connected obstructive sleep apnea, have been met. 38 U.S.C. §§ 1110, 1117, 1119, 5103, 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.310, 3.317. REASONS AND BASES FOR FINDING AND CONCLUSION The Veteran served on active duty in the U.S. Air Force from August 1992 to August 1996 with additional periods of service in the Air Force Reserve from August 1996 to August 2000 and in the Army National Guard from August 2000 to November 2001. This matter comes before the Board of Veterans' Appeals (Board) on appeal from an October 2017 rating decision by the Department of Veterans Affairs (VA) Regional Office (RO). The October 2017 rating decision reopened the claims for service connection for fatigue, GERD, and IBS and denied the claims for service connection for fatigue, GERD, and IBS. Despite the RO's action, the Board must perform its own de novo review of whether new and material evidence has been received to reopen the claims of entitlement to service connection for fatigue, GERD, and IBS before addressing the claims on their merits. See 38 U.S.C. § 7104; see also Barnett v. Brown, 83 F.3d 1380 (Fed. Cir. 1996). Pertinent to this appeal, under 38?C.F.R. §?3.156(b), for legacy claims not under the modernized review system, where new and material evidence has been received prior to the expiration of the appeal period, or prior to the appellate decision if a timely appeal has been filed, such evidence will be considered as having been filed in connection with the claim which was pending at the beginning of the appeal period. See Bond v. Shinseki, 659 F.3d. 1362, 1367 (Fed. Cir. 2011); Roebuck v. Nicholson, 20?Vet. App.?307, 316 (2006); Muehl v. West, 13?Vet. App.?159, 161-162 (1999). With respect to VA-generated medical records, these records are considered to be in the constructive, if not actual, possession of VA upon their creation. Lang v. Wilkie, 971 F.3d 1348, 1353-55 (Fed. Cir. 2020). Here, in January 2017, within one year of the December 2016 rating decision, VA received private treatment records. In the December 2016 rating decision, the RO denied service connection for IBS, because there was no evidence of a diagnosis for IBS. Those private treatments reflect that the Veteran had been receiving treatment for gastrointestinal complaints, including abdominal pain and diarrhea, since 1998 and had been diagnosed with gastroenteritis and IBS. Regarding the IBS claim, the Board finds that the private treatment records received in January 2017 are new as they were not previously of record and material as they relate to whether the Veteran has a diagnosis for a gastrointestinal disorder. Therefore, the December 2016 rating decision is not final, and the service connection claim for IBS filed in July 2016 remains pending. Accordingly, the Board will address this claim on the merits. Moreover, VA treatment records from 2006 to 2012 reflect the Veteran's treatment and diagnosis for GERD. Additionally, VA treatment records in 2013 reflect the Veteran's complaints for fatigue. Even though these records were not associated within the claims file until after the December 2016 rating decision, VA had constructive possession of these records for purposes of 38 C.F.R. § 3.156(b). In the December 2016 rating decision, the RO denied service connection for GERD, because there was no evidence of a chronic disability since service. Further, the RO denied service connection for fatigue, because there was no evidence of a current diagnosis. Regarding the GERD claim, the Board finds that the VA treatment records from 2006 to 2012 are new as they were not previously of record and material as they relate to the chronicity of the Veteran's GERD since his discharge from active duty service. Regarding the fatigue claim, the Board finds that the VA treatment records in 2013 are new as they were not previously of record and material as they relate to whether the Veteran has a diagnosis for fatigue. Therefore, the December 2016 rating decision is not final, and the service connection claims for GERD and fatigue filed in July 2016 remain pending. Accordingly, the Board will address these claims on the merits. The Veteran, as a layperson, is not competent to distinguish between competing gastrointestinal diagnoses, and so a claim of service connection for one is considered a claim for all. Clemons v. Shinseki, 23 Vet. App. 1 (2009). As such, while the Veteran's initial claim was for service connection for IBS, the Board has expanded the claim to one for service connection for a gastrointestinal disorder generally. Id. Duties to Notify and Assist Pursuant to the Veterans Claims Assistance Act (VCAA), VA has duties to notify and assist claimants in substantiating a claim for VA benefits. 38 U.S.C. §§ 5102, 5103, 5103A, 5107; 38 C.F.R. §§ 3.102, 3.156(a), 3.159. Neither the Veteran nor his representative has raised any issues with the duty to notify or duty to assist. See Scott v. McDonald, 789 F.3d 1375, 1381 (Fed. Cir. 2015) (holding that "the Board's obligation to read filings in a liberal manner does not require the Board . . . to search the record and address procedural arguments when the veteran fails to raise them before the Board."); Dickens v. McDonald, 814 F.3d 1359, 1361 (Fed. Cir. 2016) (applying Scott to a duty to assist argument). Service Connection 1. Entitlement to service connection for GERD, to include as due to a Gulf War illness, and to include as secondary to service-connected OSA The Veteran asserts that his GERD was caused by his in-service exposure to toxic substances during his Persian Gulf War service. Alternatively, the Veteran asserts that his GERD was caused or aggravated by his service-connected OSA. The Veteran reported that his GERD developed after his OSA symptoms began. He described having multiple symptoms of GERD, including heartburn with acid reflux, regurgitation of stomach contents into his throat, a sore throat with painful swallowing, difficulty swallowing, a feeling like he had a lump in his throat, chest pain that radiated into his shoulder, upper abdominal pain, nausea, vomiting, frequent coughing, and nighttime choking due to regurgitation. He said he had to use over-the-counter medication three to four times a week to control his heartburn. He was prescribed Omeprazole that he took twice a day. He also indicated that he had to avoid certain foods, like spaghetti, hot wings, fried food, pizza, and chili, which worsened his symptoms. He said that due to his GERD symptoms, he had to sleep with the head of his bed raised to fall asleep and even then, he was unable to sleep more than two straight hours, because his GERD symptoms would awaken him. See July 2021 statement. Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303(a). Generally, service connection requires: (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service. See Shedden v. Principi, 381 F.3d 1163, 1166-67 (Fed. Cir. 2004); see also Caluza v. Brown, 7 Vet. App. 498 (1995). Service connection may also be granted for any disease diagnosed after discharge when the evidence establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). In addition, service connection may be established on a secondary basis for a disability which is shown to be proximately due to or the result of a service-connected disease or injury. 38 C.F.R. § 3.310. Establishing service connection on a secondary basis requires evidence sufficient to show that a current disability exists and that the current disability was either caused by or aggravated by a service-connected disability. 38 C.F.R. § 3.310; Allen v. Brown, 7 Vet. App. 439 (1995). On August 10, 2022, the President signed into law the Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics Act of 2022 (PACT Act), Pub. L. No. 117-168, 136 Stat. 1759 (2022), which, in pertinent part, enacted under 38 U.S.C. § 1119 a presumption of toxic exposure for Persian Gulf veterans. Veterans Burn Pits Exposure Recognition Act of 2022, Pub. Law 117-168, Title II, § 302, 136 Stat. 1777 (August 10, 2022). For purposes of this presumption, any covered veteran was presumed exposed to the substances, chemicals, and airborne hazards identified in the list established and maintained by the Secretary of the Department of Veterans Affairs during the service of the covered veteran, unless there is affirmative evidence to establish that the covered veteran was not exposed to any such substances, chemicals, or hazards in connection with such service. 38 U.S.C. § 1119(b). For purposes of this presumption, the term "covered veteran" means any veteran who, on or after August 2, 1990, performed active military, naval, air, or space service while assigned to a duty station in Bahrain, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, Somalia, or United Arab Emirates, including airspace above; or, on or after September 11, 2001, performed active military, naval, air, or space service while assigned to a duty station in Afghanistan, Djibouti, Egypt, Jordan, Lebanon, Syria, Yemen, or Uzbekistan, including airspace above. 38 U.S.C. § 1119(c)(1). The PACT Act also amended 38 U.S.C. § 1117 to expand the definition of a "Persian Gulf veteran," to reduce the threshold of eligibility, and to permanently extend the period of eligibility for service connection on a presumptive basis. Accordingly, service connection may also be established on a presumptive basis for a Persian Gulf veteran who exhibits objective indications of a qualifying chronic disability that became manifest to any degree at any time. 38 U.S.C. § 1117; 38 C.F.R. § 3.317(a)(1). The term "Persian Gulf veteran" means a veteran who served on active duty in the Armed Forces in the Southwest Asia theater of operations, Afghanistan, Israel, Egypt, Turkey, Syria, or Jordan, during the Persian Gulf War. 38 U.S.C. § 1117(f). The "Southwest Asia theater of operations" refers to Iraq, Kuwait, Saudi Arabia, the neutral zone between Iraq and Saudi Arabia, Bahrain, Qatar, the United Arab Emirates, Oman, the Gulf of Aden, the Gulf of Oman, the Persian Gulf, the Arabian Sea, the Red Sea, and the airspace above these locations. 38 C.F.R. § 3.317(e)(2). The Persian Gulf War means the period beginning on August 2, 1990, through the present. 38 U.S.C. § 101(33); 38 C.F.R. § 3.2(i). A qualifying chronic disability means a chronic disability resulting from any of the following (or any combination of the following): (A) An undiagnosed illness; (B) A medically unexplained chronic multisymptom illness that is defined by a cluster of signs or symptoms, such as: (1) Chronic fatigue syndrome; (2) Fibromyalgia; (3) Functional gastrointestinal disorders (excluding structural gastrointestinal diseases). 38 C.F.R. § 3.317(a)(2)(i). Functional gastrointestinal disorders are a group of conditions characterized by chronic or recurrent symptoms that are unexplained by any structural, endoscopic, laboratory, or other objective signs of injury or disease and may be related to any part of the gastrointestinal tract. Specific functional gastrointestinal disorders include, but are not limited to, irritable bowel syndrome, functional dyspepsia, functional vomiting, functional constipation, functional bloating, functional abdominal pain syndrome, and functional dysphagia. These disorders are commonly characterized by symptoms including abdominal pain, substernal burning or pain, nausea, vomiting, altered bowel habits (including diarrhea, constipation), indigestion, bloating, postprandial fullness, and painful or difficult swallowing. Diagnosis of specific functional gastrointestinal disorders is made in accordance with established medical principles, which generally require symptom onset at least 6 months prior to diagnosis and the presence of symptoms sufficient to diagnose the specific disorder at least 3 months prior to diagnosis. Note to 38 C.F.R. § 3.317(a)(2)(i)(B)(3). For purposes of this presumption, the term "medically unexplained chronic multisymptom illness" means a diagnosed illness without conclusive pathophysiology or etiology, that is characterized by overlapping symptoms and signs and has features such as fatigue, pain, disability out of proportion to physical findings, and inconsistent demonstration of laboratory abnormalities. Chronic multisymptom illnesses of partially understood etiology and pathophysiology, such as diabetes and multiple sclerosis, will not be considered "medically unexplained." 38 C.F.R. § 3.317(a)(2)(ii). For purposes of this presumption, the term "objective indications of chronic disability" include both "signs," in the medical sense of objective evidence perceptible to an examining physician, and other non-medical indicators that are capable of independent verification. 38 C.F.R. § 3.317(a)(3). Disabilities that have existed for six months or more and disabilities that exhibit intermittent episodes of improvement and worsening over a six-month period are considered chronic. The six-month period of chronicity is measured from the earliest date on which the pertinent evidence establishes that the signs or symptoms of the disability first became manifest. 38 C.F.R. § 3.317(a)(4). Signs or symptoms that may be manifestations of an undiagnosed illness or medically unexplained chronic multisymptom illness include, but are not limited to, the following: (1) fatigue; (2) signs or symptoms involving skin; (3) headache; (4) muscle pain; (5) joint pain; (6) neurologic signs or symptoms; (7) neuropsychological signs or symptoms; (8) signs or symptoms involving the respiratory system (upper or lower); (9) sleep disturbances; (10) gastrointestinal signs or symptoms; (11) cardiovascular signs or symptoms; (12) abnormal weight loss; and (13) menstrual disorders. 38 C.F.R. § 3.317(b). In the case of claims based on an undiagnosed illness under 38 U.S.C. § 1117 and 38 C.F.R. § 3.317, unlike those for "direct service connection," there is no requirement that there be competent evidence of a nexus between the claimed illness and service. Gutierrez v. Principi, 19 Vet. App. 1, 8-9 (2004). Further, lay persons are considered competent to report objective signs of illness. Id. Compensation shall not be paid under 38 C.F.R. § 3.317 for a chronic disability: (1) if there is affirmative evidence that the disability was not incurred during active duty in the Armed Forces in the Southwest Asia theater of operations, Afghanistan, Israel, Egypt, Turkey, Syria, or Jordan during the Persian Gulf War; or (2) if there is affirmative evidence that the disability was caused by a supervening condition or event that occurred between the veteran's most recent departure from active duty in the Southwest Asia theater of operations Afghanistan, Israel, Egypt, Turkey, Syria, or Jordan and the onset of the disability; or (3) if there is affirmative evidence that the disability is the result of the veteran's own willful misconduct or the abuse of alcohol or drugs. 38 U.S.C. § 1117; 38 C.F.R. § 3.317(a)(7). Notwithstanding the provisions relating to presumptive service connection, a veteran may establish service connection for a disability with proof of actual direct causation. Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). In determining whether service connection is warranted, the Board shall consider the benefit-of-the-doubt doctrine. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102. The claimant is entitled to the benefit-of-the-doubt when the competing evidence is in "approximate balance" or "nearly equal." That is, exact equipoise is not required to trigger the favorable benefit-of-the-doubt rule. Lynch v. McDonough, 21 F.4th 776, 781 (Fed. Cir. 2021) (en banc). The question before the Board is whether the Veteran's GERD was etiologically related to service or was caused or aggravated by his service-connected OSA. Based on a careful review of all the subjective and clinical evidence, and resolving all reasonable doubt in favor of the Veteran, the Board finds that service connection for GERD is warranted. The Veteran's service records reflect that he served in the Southwest Asia theater of operations from July 1995 to December 1995. See April 2021 Information Report and December 2022 VA memorandum. Based on the circumstances of the Veteran's service, he is presumed to have been exposed to toxic substances during his active duty service. See 38 U.S.C. § 1119. The Veteran's service treatment records (STRs) document that he entered active duty service with a normal abdomen and viscera clinical evaluation. See August 1992 enlistment examination. On his associated report of medical history, he affirmatively denied having frequent indigestion and stomach, liver, or intestinal trouble. The record does not include a separation examination. Post-service VA treatment records from 2006 to 2022 document the Veteran's complaints, treatment, and diagnosis for GERD. None of the Veteran's VA providers offered an etiology for his GERD. At a November 2016 VA examination, the Veteran reported that his GERD condition began years ago when he was drinking alcohol. He said that he stopped drinking, because it made his GERD worse. He had to watch what he ate close to bedtime to avoid worsening GERD symptoms. For treatment, the Veteran said that he took Omeprazole and over-the-counter tums and antacids. The November 2016 VA examiner indicated that the Veteran had undergone an esophageal radiographic study in 2007, which the Veteran reportedly said showed he had GERD; however, the November 2016 VA examiner noted that the results could not be found. Following an objective evaluation, the November 2016 VA examiner diagnosed the Veteran with GERD. The November 2016 VA examiner opined that the Veteran's GERD "is a disease with clear and specific etiology and diagnosis so it is less likely than not that the disability pattern or diagnosed disease is related to a specific exposure event experienced by the Veteran during service in Southwest Asia." In July 2021, the Veteran submitted a June 2021 private opinion, which was prepared by G.U., an advanced practice registered nurse (APRN). The private APRN noted that her review of the Veteran's service and civilian medical records, medical literature, and the Veteran's lay statements. The private APRN opined that the Veteran's current GERD was at least as likely as not secondary to, related to, and/or aggravated by his service-connected OSA. In providing a rationale, the private APRN found that the Veteran's lay statement describing the onset of his GERD symptoms and the nature of those symptoms to be credible. Citing to medical literature discussing the pathophysiology of GERD, the private APRN emphasized that "GERD occurs when the [lower esophageal sphincter] weakens, allowing for gastric acids and other stomach contents to reflux back into the esophagus...This backflow results in the symptoms of GERD and causes esophageal tissue inflammation and irritation that can lead to erosions and abnormal cellular changes (Barrett's Esophagus) indicative of a severe impairment of health." Noting that the Veteran was service-connected for OSA, the private APRN, then included medical literature discussed the pathophysiology of OSA. Finally, the private APRN addressed the relationship between GERD and OSA. Again, citing medical literature, the private APRN explained that medical literature supported the link between GERD and OSA "based upon the pathophysiological mechanisms and processes that occur directly from the service-connected OSA to include compromised airflow. This inhibited airflow process leads to chronic oxygen deprivation to the lower esophageal sphincter and subsequently weakening the lower esophageal sphincter, thus causing the development of GERD or, at the very least, contributing as an aggravating factor in the development of the veteran's GERD." The Board recognizes that the record includes conflicting medical opinions regarding the etiology of the Veteran's GERD. With regard to the medical opinions obtained, as with all types of evidence, it is the Board's responsibility to weigh the conflicting medical evidence to reach a conclusion as to the ultimate grant of service connection. Wood v. Derwinski, 1 Vet. App. 190, 193 (1991). The Board may favor the opinion of one competent medical expert over another if its statement of reasons and bases is adequate to support that decision. Owens v. Brown, 7 Vet. App. 429, 433 (1995). Stated another way, the Board decides, in the first instance, which of the competing medical opinions or examination reports is more probative of the medical question at issue. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 300 (2008). In this case, the Board finds that the November 2016 VA examiner's opinion is inadequate, as it solely addresses whether the Veteran's GERD qualifies as a Gulf War illness under 38 C.F.R. § 3.317. In providing the unfavorable nexus opinion, the November 2016 VA examiner failed to address whether the Veteran's GERD was directly related to his presumed in-service exposure to toxic substances. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). Accordingly, the Board finds that the November 2016 VA examiner's opinion is insufficient to rely on for adjudicative purposes. Nevertheless, the record includes a favorable June 2021 opinion provided by the private APRN. In that opinion, the private APRN reviewed the Veteran's medical records, considered his lay statements regarding the onset and continuity of his GERD, addressed his assertion linking his GERD to his service-connected OSA and discussed relevant medical literature regarding the pathophysiology of both GERD and OSA as well as their relationship to each other. The Board finds that the private APRN provided a thorough analysis for her conclusions, which was supported by her review of all the relevant lay and clinical evidence. Accordingly, the Board concludes that the June 2021 private opinion provides the most persuasive evidence regarding the etiology of the Veteran's GERD. In summary, resolving all reasonable doubt in favor of the Veteran, the positive and negative evidence is in approximate balance that his GERD was caused or aggravated by his service-connected OSA. Therefore, the Veteran's service connection claim for GERD must be granted. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102. REASONS FOR REMAND 1. Entitlement to service connection for fatigue, to include as due to a Gulf War illness, and to include as secondary to GERD, is remanded. The Veteran asserts that his fatigue was caused by his in-service exposure to toxic substances or was caused or aggravated by his now service-connected GERD. At a November 2016 VA Gulf War examination, the VA examiner found that the Veteran had no additional signs and/or symptoms that may represent an undiagnosed illness or diagnosed medically unexplained chronic multisymptom illness. On that basis, there was no further examination of the Veteran's fatigue. However, shortly following that VA examination, additional relevant private treatment records and VA treatment records were associated with the record documenting the Veteran's complaints of fatigue in 2008, 2012, and 2013. Because these treatment records were not available to be considered by the November 2016 VA examiner, the Board finds that a remand is required to obtain a new VA examination addressing the Veteran's fatigue complaints. Moreover, the record only recently included the Veteran's new reasonably raised theory of entitlement that his fatigue was caused or aggravated by his service-connected GERD. See July 2021 statement. VA is obligated to consider all theories of entitlement reasonably raised by the record. See Robinson v. Peake, 21 Vet. App. 545, 553 (2008), aff'd sub nom. Robinson v. Shinseki, 557 F.3d 1355 (Fed. Cir. 2009); see also Schroeder v. West, 212 F.3d 1265, 1271 (Fed. Cir. 2000). Therefore, a remand is also required to obtain VA opinions addressing the Veteran's assertions. The Board emphasizes that it is not determining whether or not the Veteran's statements that his fatigue was caused by his in-service exposure to toxic substances or was caused or aggravated by his service-connected GERD are credible at this time, as the additional development set forth in the directives below could impact that determination. Although the Board is requesting medical opinions regarding his lay contentions, this is for thoroughness and not based on a finding that these contentions are credible. 2. Entitlement to service connection for a gastrointestinal disorder, including IBS, and to include as due to a Gulf War illness, is remanded. The Veteran asserts that his gastrointestinal problems were caused by his in-service exposure to toxic substances. At a November 2016 VA examination, the VA examiner found that the Veteran did not have a diagnosis for irritable bowel disease in his medical records. However, shortly following that VA examination, additional relevant private treatment records and VA treatment records were associated with the record documenting the Veteran's complaints and treatment for gastrointestinal symptoms, including abdominal pain, nausea, vomiting, and diarrhea, since 1998. Those records also contain multiple gastrointestinal diagnoses including gastroenteritis and IBS. Because those records were not available to be considered by the November 2016 VA examiner, the Board finds that a remand is required to obtain supplemental opinions addressing the etiology of the Veteran's gastrointestinal disorder. The Board emphasizes that it is not determining whether or not the Veteran's statements that his gastrointestinal problems were caused by his in-service exposure to toxic substances are credible at this time, as the additional development set forth in the directives below could impact that determination. Although the Board is requesting medical opinions regarding his lay contentions, this is for thoroughness and not based on a finding that these contentions are credible. The matters are REMANDED for the following actions: 1. Obtain all the outstanding treatment records for the Veteran's fatigue and gastrointestinal disorder that are not currently of record. 2. Schedule the Veteran for a VA examination to determine the nature and etiology of his fatigue by an appropriately qualified clinician. The examiner should respond to the following: (a.) The examiner is asked to opine whether the Veteran has a current diagnosis related to his reported symptoms of fatigue. (b.) If so, opine whether the Veteran's fatigue had its onset during active duty service or was otherwise etiologically related to service. (c.) If the Veteran does not have a diagnosis for fatigue, are there objective signs and symptoms of fatigue, which are manifestations of an undiagnosed illness or a medically unexplained chronic multisymptom illness? If so, please specify. (d.) If the answer to (c) is yes, please identify whether there is a clear and specific etiology. (e.) The examiner is also asked to opine whether the Veteran's fatigue was caused by the indicated toxic exposure risk activities, after considering the potential exposure through all applicable military deployments of the Veteran and the synergistic, combined effect of all toxic exposure risk activities of the Veteran. (f.) The examiner should opine whether Veteran's fatigue was caused by his service-connected GERD. (g.) The examiner should opine whether the Veteran's fatigue was aggravated beyond its natural progression by his service-connected GERD. In providing the above opinions, the examiner must note that the Veteran is presumed to have been exposed to toxic substances during active duty service. The examiner should also address the Veteran's complaints of fatigue in private treatment records dated 2008 and in VA treatment records in 2012 and 2013. The examiner must address the Veteran's reports in a July 2021 statement that due to his GERD, he was unable to sleep more than two straight hours from being awakened by his GERD symptoms, which caused him to experience daytime fatigue. The examiner must not rely solely on the lack of medical documentation as the basis for a negative opinion. A complete rationale with discussion of medical literature for any opinion expressed must be provided. If an opinion cannot be expressed without resort to speculation, discuss why this is the case. 3. Arrange for an addendum opinion from an appropriately qualified clinician for the Veteran's gastrointestinal disorder. Only if deemed necessary to provide an opinion, should the Veteran be afforded a new VA examination for his gastrointestinal disorder. The examiner should respond to the following: (a.) The examiner is asked to opine whether the Veteran has a current diagnosis for a gastrointestinal disorder, other than GERD. (b.) If so, opine whether the Veteran's gastrointestinal disorder had its onset during active duty service or was otherwise etiologically related to service. (c.) If the Veteran does not have a diagnosis for a gastrointestinal disorder, are there objective signs and symptoms of gastrointestinal problems, which are manifestations of an undiagnosed illness or a medically unexplained multisymptom illness? If so, please specify. (d.) If the answer to (c) is yes, please identify whether there is a clear and specific etiology. (e.) The examiner is also asked to opine whether the Veteran's gastrointestinal disorder was caused by the indicated toxic exposure risk activities, after considering the potential exposure through all applicable military deployments of the Veteran and the synergistic, combined effect of all toxic exposure risk activities of the Veteran. In providing the above opinions, the examiner must note that the Veteran is presumed to have been exposed to toxic substances during active duty service. The examiner must address the Veteran's complete medical history and complaints of gastrointestinal problems as documented in private and VA treatment records since 1998. The examiner must not rely solely on the lack of medical documentation as the basis for a negative opinion. A complete rationale with discussion of medical literature for any opinion expressed must be provided. If an opinion cannot be expressed without resort to speculation, discuss why this is the case. (Continued on the next page) ? 4. Thereafter, review the requested VA medical examination and opinion reports to ensure responsiveness and compliance with the directives of this remand; implement corrective procedures as needed. Compliance with the Board's remand instructions is neither optional nor discretionary. Stegall v. West, 11 Vet. App. 268 (1998). 5. After ensuring the above development has been completed, readjudicate the issues on appeal. If the benefits sought on appeal are not granted to the Veteran's satisfaction, send the Veteran and his representative a supplemental statement of the case and provide an opportunity to respond. Then, return the case to the Board for further appellate review. LESLEY A. REIN Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Journet Shaw, Counsel The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.