Irritable Bowel Syndrome Ibs Medication

The most commonly prescribed IBS medications include:

  • low-dose antidepressants to control abdominal nerve endings
  • antispasmodics to control intestinal muscle spasm and abdominal pain
  • musculotropic antispasmodics to relieve spasms in the smooth muscle cells and intestines
  • medications that slow down the speed of food moving through the digestive system
  • laxatives.

IBS Medications by Symptom

For diarrhea . . .

Good results have been achieved with loperamide, either taken on its own or in combination with an antispasmodic drug such as dicyclomine or hyoscyamine. The latter are particularly effective for the control of abdominal cramping.

For constipation . . .Stimulant laxatives are best avoided, as they only tend to irritate the bowel. Osmotic laxatives, such as lactulose or sorbitol are preferred alternatives.

For severe abdominal pain . . .Besides antispasmodic drugs, low-dose antidepressants may also be prescribed for the treatment of severe abdominal pain and cramping. Antidepressants work by blocking the transmission of pain from the nerve endings in the intestine to the brain.

Low-dose antidepressants are just as effective for the control of IBS symptoms as the same antidepressants taken in higher doses for the treatment of depression.


On June 7th, 2002, the Food and Drug Administration (FDA) approved the restricted marketing of the drug Lotronex (alosetron hydrochloride) for the treatment of women “with severe diarrhea-predominant irritable bowel syndrome ” who previously “had failed to respond to conventional IBS therapy. “

Although the FDA approved this drug application permitting the restricted marketing of Lotronex, the authority to prescribe the drug remains limited to certain physicians. The aim is to target only those patients with severe IBS symptoms and for whom the drug is most appropriate.

Such caution is necessary because of the potential side effects of the drug, which include severe complications resulting from constipation, gastrointestinal aggravation and, in extreme instances, death.


Donnatal is an antispasmodic drug that has two main components: belladonna and phenobarbital. It is a mild sedative that relaxes the muscles of the intestines.

Other brand names for Donnatal include Donnapine®, Barbidonna®, Hyosophen® and Spasmolin®.


The drug branded as Zelnorm in the USA and Canada, is currently available in more than twenty other countries worldwide, where it is perscribed under the brand name Zelmac.

On July 24th, 2002, Zelnorm (tegaserod maleate) received approval from the FDA. Manufactured by Novartis Pharmaceuticals Corporation, Zelnorm is the first US prescription medication approved for the treatment of combined symptoms of IBS, including constipation, abdominal pain and bloating.

Zelnorm is currently the only FDA approved prescription medication available in the US for the short-term treatment of women with multiple irritable bowel syndrome symptoms.

According to Dr. John Kellow, Associate Professor of Medicine, University of Sydney, “Zelmac represents the most promising prescription treatment for many years for those affected by IBS with constipation and who have found dietary, lifestyle changes and other currently available remedies to be of little benefit. “

Resources (updated 2005). Treatment strategies for (updated 2005). Zelnorm/Zelmac information.Beers, M.H.,