IBS Secondary to PTSD

If your PTSD is service connected and a doctor has diagnosed you with irritable bowel syndrome (IBS), you can claim the IBS as secondary to the PTSD. The Board has granted it, including for a veteran whose IBS was diagnosed years before the PTSD. The hard part is showing, with your own records, how the two are linked in you. If you served in the Persian Gulf War, a Gulf War rule may give you a second route that needs no PTSD link. This page covers the research, how VA decides and rates the claim, the Gulf War route, and what the nexus letter needs.

Can PTSD cause IBS?

The research shows a consistent link. It does not settle which condition comes first, and a careful opinion says so.

• A 2019 meta-analysis of eight studies with 648,375 people, most of them U.S. Army veterans (Ng and colleagues, Journal of Gastroenterology and Hepatology), found PTSD tied to higher odds of IBS (pooled odds ratio 2.80).
• A study of 603,221 Iraq and Afghanistan veterans new to VA care (Maguen and colleagues, Depression and Anxiety, 2014) found that veterans with a mental health diagnosis were at least twice as likely to have a digestive disorder. IBS was the digestive disorder most strongly tied to mental health conditions, and among men the added risk of IBS was greatest with PTSD.
• In a study of 184 veterans with PTSD (Kearney and colleagues, Journal of Clinical Gastroenterology, 2022), a quarter met research criteria for IBS, and more severe PTSD went with worse constipation, diarrhea and bloating.

The 2019 meta-analysis describes PTSD as marked by hyperarousal and hypervigilance and points to the gut-brain axis, the signaling that runs both ways between the gut and the brain, as the link under study.

Not every finding points one way. A 2023 genetic study (Zhou and colleagues, Psychological Medicine) found that PTSD and IBS share genetic risk, and its tests for cause and effect pointed from IBS to PTSD, with no sign of PTSD causing digestive disorders other than reflux. A study of 337 women veterans (White and colleagues, Alimentary Pharmacology and Therapeutics, 2010) found trauma itself tied to IBS even after accounting for PTSD and depression. And a study of 4,680 male twins from the Vietnam Era Twin Registry found that shared genes and shared environment explain part of the overlap between PTSD and chronic pain conditions, IBS among them (Gasperi and colleagues, Psychosomatic Medicine, 2021). Findings like these are why the opinion has to rely on your own timeline, and why aggravation matters when the IBS came first.

How VA decides IBS secondary to PTSD

Secondary service connection is in 38 CFR § 3.310. VA grants it in two ways:

• Caused by. Your service-connected PTSD caused the IBS, at least as likely as not.
• Aggravated by. Your IBS is aggravated by your service-connected PTSD, meaning it would be less severe but for the PTSD (M21-1 V.ii.2.D). VA rates only the part above the baseline, so the opinion should describe the baseline.

The claim needs three things in the file: a current IBS diagnosis, service-connected PTSD, and a medical opinion linking the two with reasoning. Confirm the diagnosis first. A claim built on "stomach problems" fails before anyone reaches the link, so keep the records of what other causes your clinician considered. The same rules apply to other conditions claimed secondary to PTSD, such as GERD secondary to PTSD and sleep apnea secondary to PTSD.

If your IBS came before your PTSD

The claim is not over. It becomes a question of aggravation. Under § 3.310(b), VA will not concede aggravation unless the baseline severity is shown by medical evidence created before the aggravation began, or by the earliest medical evidence created after it. Your oldest IBS records show the baseline, and later records show what changed.

The Board granted exactly this kind of claim in Board citation A25028989 (March 2025). The veteran, who served in Vietnam, had GERD and IBS diagnosed in 2006 and 2011 and PTSD in 2019. Several VA examiners reasoned that conditions diagnosed before PTSD could not have been caused by it, and either did not address aggravation or dismissed it without explanation. One VA examiner explained that PTSD's hyperarousal can signal the gut to work in that same state, which may cause constipation and diarrhea, and a private doctor wrote that PTSD had at least aggravated the symptoms. The Board found the negative opinions inadequate because an opinion must give separate reasons for causation and aggravation, and granted IBS and GERD as secondary to PTSD on an aggravation basis. Board decisions are not precedential, but they show what the Board accepts.

VA rating for IBS secondary to PTSD

IBS secondary to PTSD is rated the same way as any IBS, under 38 CFR § 4.114, Diagnostic Code 7319, as revised effective May 19, 2024. Every level requires abdominal pain related to defecation, plus two or more of these: a change in stool frequency, a change in stool form, altered stool passage (straining or urgency), mucus in the stool, abdominal bloating, or a feeling of distension.

• 30%: abdominal pain related to defecation at least one day per week during the previous three months
• 20%: abdominal pain related to defecation at least three days per month during the previous three months
• 10%: abdominal pain related to defecation at least once during the previous three months

When the requirements for 10 percent are not met, VA assigns 0 percent (38 CFR § 4.31). Older guides that describe mild, moderate or severe IBS are describing the criteria VA replaced in 2024. The IBS VA rating page covers the current criteria and what a symptom log should record.

VA rates the IBS separately from the PTSD, because IBS has its own diagnostic code. The two ratings combine under 38 CFR § 4.25. A 70% PTSD rating and a 20% IBS rating combine to 76, which VA rounds to 80%. If VA grants the IBS on aggravation, the rating reflects only the part above your baseline.

Within the digestive system there is a limit. Section 4.114 says ratings under diagnostic codes 7301 through 7329, and several others, are not combined with each other. VA assigns one rating under the code for the predominant problem and can raise it one level if the overall picture warrants. IBS is DC 7319, so another digestive condition in that group means one digestive rating, not two.

The Gulf War route for IBS

If you are a Persian Gulf veteran, you may not need the PTSD link. Under 38 CFR § 3.317, VA pays compensation to a Persian Gulf veteran with a qualifying chronic disability, which includes functional gastrointestinal disorders (excluding structural gastrointestinal diseases). The regulation's note names irritable bowel syndrome among them.

• The PACT Act changed the law in 2022. Under 38 U.S.C. § 1117(a)(1), the condition now only has to have "become manifest to any degree at any time," and the law no longer has an end date. The regulation, § 3.317, has not been rewritten to match and still prints a December 31, 2026 date and a 10 percent threshold.
• It counts as chronic once it has lasted six months or more, or has come and gone over a six-month period.
• A Persian Gulf veteran is one who served during the Persian Gulf War in the Southwest Asia theater of operations (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 them). Since the PACT Act, 38 U.S.C. § 1117(f) also counts service in Afghanistan, Israel, Egypt, Turkey, Syria or Jordan.
• There are exceptions, such as affirmative evidence that the condition was not incurred in the theater or was caused by a later event.

The Gulf War illness page covers this route in more detail. An accredited representative can help you decide whether to present the Gulf War route, the PTSD route or both.

The C&P exam for IBS secondary to PTSD

VA usually orders an exam or a medical opinion for this claim. The examiner is asked whether your IBS is at least as likely as not caused by your PTSD and, separately, whether the PTSD aggravated it. Both questions matter. An opinion that answers only the first one is inadequate under El-Amin v. Shinseki (2013).

What the examiner looks at:

• Who diagnosed the IBS, on what basis, and what other causes were ruled out
• When your bowel symptoms began, compared with your PTSD symptoms and treatment
• Records from before and after the PTSD began or worsened, which set the baseline
• Treatment notes that tie flares to stress, anxiety or PTSD symptoms
• How often you have pain related to bowel movements over the previous three months, and which listed symptoms come with it

Unfavorable opinions can go wrong in a few ways. In the case above, VA examiners stopped at "the IBS came first," one said no medical literature supports a link, and one dismissed aggravation without a reason. The research above answers the literature point, and an earlier diagnosis points to aggravation, not to a denial. C&P exam prep can help you describe your symptom pattern in the terms the rating uses. The Board section below shows how the Board handled VA opinions on this pair.

Why IBS secondary to PTSD claims get denied

These are the gaps that sink a claim like this:

• No confirmed IBS diagnosis, or no record of what else was considered.
• The only medical opinion is a negative VA opinion, and nothing in the file answers it.
• The opinion addresses causation and never addresses aggravation.
• The IBS is documented before the PTSD, but the claim argues only that PTSD caused it.
• A private opinion states a conclusion with no reasoning, or does not deal with other explanations in your records.
• The records do not show how often pain related to bowel movements happens, so even a grant lands at a low rating.

The Board section below breaks down the evidence that decided the grants and the denials.

Nexus letter for IBS secondary to PTSD

A strong nexus letter for this claim does five things:

1. States that the doctor reviewed your records, including the IBS diagnosis and workup, your PTSD treatment history and your earliest bowel complaints.
2. Gives an opinion on causation: your IBS is at least as likely as not caused by your service-connected PTSD.
3. Gives a separate opinion on aggravation: your IBS is aggravated by your service-connected PTSD, meaning it would be less severe but for the PTSD, and describes the baseline from your oldest IBS records.
4. Explains the reasoning in plain medical terms, cites the research, and says where its limits matter for your facts, such as the shared genetic risk and the question of which came first.
5. Deals with other explanations for your symptoms and says how they change the conclusion.

Questions to bring to the doctor:

• Is the IBS diagnosis well supported, and what other causes were considered?
• In my history, did PTSD cause the IBS, make existing IBS worse, or neither?
• If the IBS came first, would it be less severe today but for the PTSD, and which records show its baseline?
• Which studies apply to my facts, and where do their limits matter?

A clinician may find the evidence insufficient or another cause more persuasive. Where these opinions break down at the Board is predictable: no rationale, a conclusion with no reasoning behind it, an incomplete review of the records, or a specialty that does not fit the question. Raven Nexus pulls the key passages from your records and the research into an organized draft your doctor can review.

Questions veterans ask about IBS secondary to PTSD

Is IBS secondary to PTSD?

It can be. VA can grant IBS secondary to PTSD under 38 CFR § 3.310 when PTSD caused it or made it worse. A medical opinion has to explain the link in your own records.

Can IBS be secondary to PTSD if the IBS was diagnosed first?

Yes, on aggravation. Your oldest IBS records set the baseline, and the opinion has to say your IBS would be less severe but for the PTSD. The Board granted a claim like this in March 2025.

What is the VA rating for IBS secondary to PTSD?

The same as any IBS under Diagnostic Code 7319: 10, 20 or 30 percent, based on how often pain related to bowel movements happened over the previous three months, plus two or more listed symptoms. The rating then combines with your PTSD rating; for example, 70 percent PTSD and 20 percent IBS combine to 80 percent.

Do Gulf War veterans need to link IBS to PTSD?

Maybe not. For a Persian Gulf veteran, 38 CFR § 3.317 treats IBS as a qualifying chronic disability. Since the PACT Act, the law requires only that it became manifest to any degree at any time, subject to exceptions.

What records help an IBS secondary to PTSD claim?

The PTSD rating decision, the IBS diagnosis and the tests that ruled out other causes, your earliest bowel complaints with dates, notes from before and after your PTSD began or worsened, and any prior opinions in full. A personal statement can describe how your symptoms changed.

Sources

• 38 CFR § 3.310, secondary service connection; M21-1 V.ii.2.D, aggravation of a nonservice-connected disability by a service-connected one.
• 38 CFR § 4.114, Diagnostic Code 7319, irritable bowel syndrome, and the rule against combining certain digestive ratings; 38 CFR § 4.31, zero percent evaluations; 38 CFR § 4.25, combined ratings table.
• 38 CFR § 3.317, compensation for certain disabilities in Persian Gulf veterans; 38 U.S.C. § 1117(a)(1) and (f) as amended by the Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics Act of 2022 (PACT Act), Pub. L. 117-168, § 405.
• El-Amin v. Shinseki, 26 Vet. App. 136 (2013), an opinion must address aggravation.
• Ng QX, Soh AYS, Loke W, Venkatanarayanan N, Lim DY, Yeo WS. Systematic review with meta-analysis: The association between post-traumatic stress disorder and irritable bowel syndrome. Journal of Gastroenterology and Hepatology. 2019;34(1):68-73. PMID 30144372.
• Maguen S, Madden E, Cohen B, Bertenthal D, Seal K. Association of mental health problems with gastrointestinal disorders in Iraq and Afghanistan veterans. Depression and Anxiety. 2014;31(2):160-165. PMID 23494973.
• Kearney DJ, Kamp KJ, Storms M, Simpson TL. Prevalence of Gastrointestinal Symptoms and Irritable Bowel Syndrome Among Individuals With Symptomatic Posttraumatic Stress Disorder. Journal of Clinical Gastroenterology. 2022;56(7):592-596. PMID 35089910.
• Zhou S, Luo H, Tian Y, et al. Investigating the shared genetic architecture of post-traumatic stress disorder and gastrointestinal tract disorders: a genome-wide cross-trait analysis. Psychological Medicine. 2023;53(16):7627-7635. PMID 37218628.
• White DL, Savas LS, Daci K, et al. Trauma history and risk of the irritable bowel syndrome in women veterans. Alimentary Pharmacology and Therapeutics. 2010;32(4):551-561. PMID 20528828.
• Gasperi M, Panizzon M, Goldberg J, Buchwald D, Afari N. Posttraumatic Stress Disorder and Chronic Pain Conditions in Men: A Twin Study. Psychosomatic Medicine. 2021;83(2):109-117. PMID 33337593.
• Board of Veterans' Appeals citation A25028989 (granted). Board decisions are not precedential.
• Board figures on this page: Claim Raven's read of every Board decision from 2021 to 2026 that it holds, and of every decision since 1992 for the longer view.