Show Summary Details
Page of

Irritable bowel syndrome 

Irritable bowel syndrome
Irritable bowel syndrome

Adam D. Farmer

, and Qasim Aziz

Page of

PRINTED FROM OXFORD MEDICINE ONLINE ( © Oxford University Press, 2021. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 03 March 2021

Symptoms suggestive of disturbed lower gastrointestinal function without adequate explanation are very common in adults in the Western world, up to 15% of whom experience such symptoms at any one time, although most do not seek medical advice. The currently used terms are best viewed as an attempt to provide some clinically useful, rather than pathophysiologically accurate, categorization of patients and their symptoms based on disordered gut–brain interactions. Irritable bowel syndrome is defined according to the Rome III criteria as recurrent abdominal pain or discomfort associated with a change in bowel habit for at least 6 months, with symptoms experienced on at least 3 days of at least 3 months. Many subtypes are recognized. Routine haematological and biochemical screening is usually performed on the assumption that it will be normal. Features that raise the suspicion of organic disease and indicate a need for further investigation include the onset of symptoms in middle-aged or older individuals, weight loss, or blood in the stool. Management remains empirical: no single pharmacological agent or group of agents has ever been found to be consistently effective. The principal task of the physician is to provide explanation and reassurance (sometimes supplemented by psychological treatments), but particular symptoms are often treated as follows: (1) constipation—defecation may be eased by supplementary dietary fibre and poorly absorbed fermentable carbohydrates which increase faecal bulk and soften the stool; osmotic laxatives and enemas are used for the severely constipated patient, as well as more novel agents; (2) diarrhoea—attention to diet is often helpful, as are simple antidiarrhoeal agents; and (3) abdominal pain—antispasmodics (e.g. hyoscine butyl bromide) are frequently used, as are antidepressants.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.