The main treatment for irritable bowel syndrome (IBS) is making dietary and lifestyle modifications, including stress management and exercise. Avoiding fatty foods and caffeine may also help. Symptom-specific treatment for IBS includes products to alleviate diarrhoea, constipation and pain.
Anti-diarrhoeal drugs such as loperamide (e.g. Imodium) and atropine plus diphenoxylate (e.g. Lomotil) are effective when taken ‘as-needed’ on an intermittent basis. Stool bulking with fibre (dietary or supplemental) may also be worthwhile. However, fibre should be introduced gradually to minimise the side effects of abdominal gas and bloating.
The first step in the treatment of constipation-predominant symptoms should be through dietary changes, including daily consumption of a high-fibre cereal, high-fibre breads and plenty of fresh fruits and vegetables. You should also increase your fluid intake and take regular exercise. If up to 30 grams of dietary fibre per day is not effective, you should try supplemental fibre, such as psyllium.
If constipation is severe, increased fibre may be ineffective and may worsen abdominal pain and bloating. In this case you should take osmotic laxatives or, in more resistant cases, a stool-softener such as docusate, with or without enemas. Stimulant laxatives such as senna should generally be avoided, as should prolonged use of any laxative.
Psyllium (e.g. Metamucil), frangula with sterculia (Normacol Plus), lactulose (e.g. Actilax), sorbitol (e.g. Sorbisol) and docusate (e.g. Coloxyl) are some of the over-the-counter products available to relieve constipation. However, people with irritable bowel syndrome tend to find the side effects of lactulose and sorbitol difficult to manage.
Medicines that relieve abdominal cramping should be used ‘as-needed’, rather than on a regular basis. These medicines may also be used preventively when pain is predicted, such as after large meals.
Prescription and over-the-counter products that help alleviate the pain associated with IBS include peppermint oil (e.g. Mintec), hyoscine butylbromide (e.g. Buscopan), hyoscyamine (Donnatab) and mebeverine (e.g. Colofac, Colese).
Some antidepressant medicines including tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs), when taken in low doses, may be beneficial in reducing pain in people with IBS. In these situations the antidepressant medicines are being used for their pain-relieving properties rather than for their effect on mood.
Last Reviewed: 29 August 2012