What are treatments for constipation from irritable bowel syndrome (IBS)?

Bulking agents that contain psyllium -- for example, Metamucil, Fiberall, Hydrocil, and Konsyl -- improve overall symptoms of constipation from irritable bowel syndrome (IBS); but the American College of Gastroenterology (AGS) panel found that neither wheat bran nor corn bran is better than a placebo in managing IBS. Lubiprostone (Amitiza) is effective in relieving overall symptoms of women with constipation-predominant IBS, but should not be taken by women who are or could become pregnant. Tegaserod (Zelnorm) also helps relieve overall symptoms of women with constipation-predominant IBS. It was briefly removed from the market because of a slight increase in cardiovascular risk and is now available only to women under age 55 who are in critical need of it and have no known heart problems. The AGS experts didn't find much evidence for laxatives, but many clinicians think these may be safe and effective when used judiciously. However, laxatives with stimulant properties (such as Dulcolax, Senokot, and Ex-Lax) may cause some cramping.