Clinical Question

What is the best way to manage irritable bowel syndrome (IBS)?

Bottom Line

This high-quality evidence-based guideline provides sound advice for the evaluation and management of IBS in primary care. (Level of Evidence = 1a)

Synopsis

The guidelines from the British Society of Gastroenterology were created by a multidisciplinary panel that included primary care physicians, psychologists, dietitians, and gastroenterologists. Treatment recommendations were based on systematic reviews, and other recommendations were based on a comprehensive review of the literature. There are dozens of recommendations; this POEM outlines the highlights. The guidelines advocate a pragmatic definition of IBS as at least six months of abdominal pain or discomfort with altered bowel habits, and the absence of alarm signs or symptoms. Initial evaluation in primary care should include a complete blood count, C-reactive protein or sedimentation rate, and serology for celiac disease. For patients younger than 45 years who present with diarrhea, order a fecal calprotectin test to rule out inflammatory bowel disease. 

Screen for colorectal cancer in accordance with national guidelines; colonoscopy is only recommended for patients with alarm signs and symptoms or who are at increased risk of microscopic colitis (women; patients 50 years and older; those with comorbid autoimmune disease, weight loss, diarrhea for less than 12 months, or nocturnal or severe, watery diarrhea). Consider testing for bile acid diarrhea in patients with nocturnal diarrhea or prior cholecystectomy. The guidelines recommend against testing for pancreatic insufficiency, small intestinal bacterial overgrowth, or carbohydrate intolerance if the symptoms are typical for IBS. 

First-line treatment recommendations include exercise and gradually increasing doses of soluble fiber (e.g., ispaghula) but not insoluble fiber (e.g., wheat bran). Probiotics can be considered, although the guideline does not recommend a specific species or dose. Consider loperamide (Imodium) for diarrheal symptoms; antispasmodics and peppermint oil (a recent POEM reported that a well-designed trial found no benefit with peppermint oil) for global symptoms and abdominal pain and cramping; and polyethylene glycol (Miralax) for constipation. Second-line medications in primary care include tricyclic antidepressants and selective serotonin reuptake inhibitors. Other drug classes, such as medications targeting 5-HT3 and 5-HT4 receptors, should be prescribed after evaluation by a gastroenterologist. 

Study design: Practice guideline 

Funding source: Foundation 

Setting: Outpatient (any) 

Reference: Vasant DH, Paine PA, Black CJ, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021;70(7):1214–1240.

Editor's Note: Dr. Ebell is deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell.