How it works: Acts on specific serotonin receptors targeting nerves in the intestinal tract. These nerves can sense pain and are responsible for bowel function.

Which symptoms does it help: Overall symptoms in women with IBS-C, constipation, belly pain.

How long it takes to see a benefit: 1-2 weeks.

FDA approved: Women with IBS-C under the age of 65 years.

Dosage: 6 mg twice a day.

Special considerations or risks: Tegaserod is contraindicated in patients with a history of cardiovascular (MI or angina) or cerebrovascular (stroke or TIA) disease, history of ischemic colitis, history of bowel obstruction, symptomatic gallbladder disease, suspected sphincter of Oddi dysfunction, abdominal adhesions, severe renal impairment, or moderate to severe liver impairment. Monitoring for clinical worsening of depression and emergence of suicidal thoughts, especially during the initial few months of treatment, is required.

Most common side effects: Headache, abdominal pain.

Recommendation: ACG suggests tegaserod for IBS-C symptom improvement in women younger than 65 years of age.