Health condition
Common variable immunodeficiency gut
Common variable immunodeficiency (CVID) - the most frequent serious antibody deficiency - commonly affects the gut, causing chronic diarrhoea, malabsorption, a coeliac-like enteropathy and higher risks of infection and inflammation.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key points
What matters most, at a glance.
The essentials in plain English - symptoms, when to seek help, who to see and what treatment looks like.
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Gut symptoms affect a substantial minority of people with CVID; recurrent chest and sinus infections are the usual first clue to the underlying deficiency
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Giardia infection is disproportionately common and treatable - stool PCR is an early test in any CVID diarrhoea
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The CVID enteropathy resembles coeliac disease on biopsy but typically lacks plasma cells and does not respond to gluten exclusion
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Nodular lymphoid hyperplasia and inflammatory bowel-like disease also occur and need tailored treatment
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Immunoglobulin replacement treats infections but not the enteropathy, which may need immunomodulation
Understanding it
About Common variable immunodeficiency gut, and what to do next.
Antibody-deficient gut mucosa is doubly vulnerable: infections such as giardia, campylobacter and norovirus persist and injure the lining, while dysregulated immunity drives inflammation of its own. Any adult with unexplained enteropathy and low immunoglobulins - or a history of endless sinus and chest infections - deserves formal immunological assessment.
Joint gastro-immunology care sorts infection from inflammation with stool diagnostics, biopsy and calprotectin, then treats each appropriately - antimicrobials for pathogens, budesonide or systemic agents for the enteropathy - alongside optimised immunoglobulin replacement and nutritional support. Most people start with their GP, who can refer to a consultant gastroenterologist jointly with a clinical immunologist. In many parts of the UK, routine NHS referrals for this kind of problem currently take 20-45+ weeks, whereas an initial private consultation is typically available within around two weeks.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any emergency symptoms described above.
Frequently asked
Common questions about Common variable immunodeficiency gut.
Quick, plain-English answers to what people ask us most.
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How does common variable immunodeficiency affect the gut?
Common variable immunodeficiency (CVID) can affect the digestive system in several ways, including an increased susceptibility to gut infections, a condition resembling inflammatory bowel disease, and malabsorption of nutrients, all related to the underlying immune dysfunction affecting antibody production. Gut symptoms are a recognised and sometimes significant feature of CVID beyond the more commonly known increased susceptibility to respiratory infections. Recognising these gut-related features is important for comprehensive management of the condition.
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What gut symptoms occur with CVID?
Symptoms can include chronic or recurrent diarrhoea, abdominal pain, bloating, and weight loss, sometimes related to specific gut infections that are more common or harder to clear due to the underlying immune deficiency, and sometimes related to a non-infectious inflammatory process affecting the bowel lining, sometimes described as CVID-associated enteropathy. The specific pattern and cause of gut symptoms can vary between individuals with CVID. A thorough gastroenterology assessment helps identify the specific cause in each case.
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Why does CVID cause these gut problems?
CVID involves reduced production of antibodies, which are important for the immune system's normal function in fighting infection and, it's increasingly recognised, in maintaining healthy regulation of the gut immune system and its interaction with gut bacteria. This can lead to both an increased risk of specific infections (such as with certain parasites or bacteria) and, separately, an inflammatory process within the bowel that resembles other inflammatory bowel conditions but has some distinct features. Ongoing research continues to better understand these gut-related mechanisms in CVID.
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Is gut involvement in CVID serious?
Yes, it can be, contributing to significant symptoms, nutritional deficiencies, and reduced quality of life if not properly identified and managed, and in some cases can be a challenging aspect of CVID to treat effectively. With appropriate specialist gastroenterology and immunology input, however, many people achieve reasonable control of their gut symptoms. Regular monitoring helps identify and address any gut-related complications as they develop.
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How is gut involvement in CVID treated?
Treatment depends on the specific cause identified — treating any specific infections found, using anti-inflammatory or immune-modulating treatments for CVID-associated enteropathy (similar in some ways to treatments used for inflammatory bowel disease), and addressing any nutritional deficiencies through supplementation or dietary support. Close collaboration between immunology and gastroenterology specialists is generally needed given the specific and sometimes complex nature of gut involvement in CVID. Treatment is individualised based on the specific findings from investigation.
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When should I see a specialist?
If you have CVID and develop persistent digestive symptoms, or these symptoms haven't been fully assessed, gastroenterology review alongside your existing immunology care is worthwhile. NHS gastroenterology referral can take several weeks; a private consultation is typically available within about 2 weeks for earlier specialist assessment.