More than just IBS: the expanded world of bowel DGBIs

More than just IBS: the expanded world of bowel DGBIs

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Abstract

When people think of chronic gut issues, irritable bowel syndrome (IBS) is usually the first name mentioned. But under the updated Rome V criteria, IBS is just one member of a larger family known as Bowel Disorders / bowel DGBIs - conditions in which intestinal motility, sensitivity and communication with the central nervous system are disturbed [1].

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The big update: the return of "discomfort"

One of the most significant shifts in Rome V was the formal reintroduction of the word "discomfort" alongside "pain" for diagnosing IBS [1]. If you experience chronic bloating, pressure or a vague sense of gut unease paired with altered bowel habits, you no longer fly under the diagnostic radar [1].

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The six subtypes of bowel DGBIs

Rome V splits bowel disorders into six distinct clinical buckets [1]:

1. Irritable bowel syndrome (IBS) - chronic abdominal pain or discomfort linked to changes in stool form or frequency. Divided into IBS-C (constipation), IBS-D (diarrhoea), IBS-M (mixed) and IBS-U (unclassified). EndoCap has a page covering the IBS subtypes in detail.
2. Chronic constipation - persistent hard, infrequent or difficult-to-pass stools without dominant abdominal pain.
3. Functional diarrhoea - recurring loose stools without identifiable organic disease or pain.
4. Functional bloating and distension - chronic feelings of internal fullness or measurable abdominal swelling that overshadow other symptoms.
5. Unclassified bowel disorder - for patients who clearly have a gut-brain bowel malfunction but don't neatly fit the criteria above.
6. Opioid-induced constipation (OIC) - caused by a drug, but classified here because it mimics functional constipation mechanisms.

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A shift toward "positive diagnosis"

The era of treating bowel DGBIs as a "diagnosis of exclusion" - running dozens of invasive tests before naming the condition - is officially over [1]. Rome V encourages clinicians to make a confident, positive diagnosis based on symptom patterns and extend the work-up with invasive tests such as colonoscopy mainly when clear alarm features are present. Faecal calprotectin is not an invasive test, and the British IBS guideline describes it as relevant already at first assessment of younger patients with diarrhoea-predominant symptoms, precisely to separate irritable bowel syndrome from inflammatory bowel disease (BSG 2021). The same applies to blood tests and coeliac screening. Alarm features include: rectal bleeding, weight loss, anaemia, onset over 50, or family history of bowel cancer [1].

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Treatment

Treatment is multimodal and tailored to subtype: low-FODMAP diet, antispasmodics, neuromodulators, probiotics and psychological interventions (CBT, gut-directed hypnotherapy) [1].

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Work-up at Kirurgen.dk

We offer colonoscopy, sigmoidoscopy, coeliac screening, faecal calprotectin and structured IBS work-up. Continue the series: Oesophageal DGBIs, Gastroduodenal DGBIs, Centrally mediated pain, Anorectal DGBIs.

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References

1. Corsetti M, Shin A, Lacy BE, Cash BD, Simrén M, et al. Bowel Disorders. Gastroenterology 2026;170(6):1261-1282. DOI: 10.1053/j.gastro.2026.02.003. PubMed - verified Rome V source document. The chapter is the Rome V text on bowel disorders and is used here as documentation of the Rome V framework itself.