Management of Diarrhea in Irritable Bowel Syndrome (IBS)

First-Line Treatments

The American Gastroenterological Association recommends regular exercise to all IBS patients as it can improve overall symptoms 1, 3
First-line dietary advice should include increasing soluble fiber (e.g., ispaghula/psyllium) starting at low doses (3-4g/day) and gradually increasing to avoid bloating, as suggested by the National Institute for Health and Care Excellence 1, 2
A low FODMAP diet may be considered as second-line dietary therapy, but should be supervised by a trained dietitian with planned reintroduction of foods according to tolerance, according to the British Dietetic Association 2, 5
Loperamide (4-12mg daily) effectively reduces stool frequency and urgency in IBS-D patients, as recommended by the American College of Gastroenterology 1, 6

Tricyclic antidepressants (TCAs) are effective second-line treatments for global symptoms and abdominal pain in IBS, as suggested by the American Gastroenterological Association 2, 5
5-HT3 receptor antagonists are among the most efficacious drugs for IBS-D, according to the European Society of Gastrointestinal Motility 5, 8

Consider bile acid malabsorption in patients with IBS-D who have atypical features such as nocturnal diarrhea or prior cholecystectomy, as recommended by the National Institute for Health and Care Excellence 1, 4
Referral to gastroenterology is warranted when there is diagnostic doubt, symptoms are severe or refractory to first-line treatments, or the patient requests specialist opinion, according to the American Gastroenterological Association 1, 4