I was on Effexor briefly to treat IBS. It's common for doctors to use antidepressants, esp. the trycliclic types, in an initial attempt to treat IBS symptoms. After trying many different antidepressants, I found that none of them worked, or even helped. All they did was give me bad side effects, such as headaches, stomach aches, dry mouth, and feeling "spacy", or extreme drousiness. Antispasmodic drugs are more likely to help. Librax is a combo drug--it has an antispasmodic drug and an anti-anxiety drug combined. After years of trial and error, I'm on an anti-anxiety drug--Xanax, and a strong anti-diarhea drug. For diarhea, I tried Immodium, then Lomotil, then Librax, then Levsin.A couple of years ago my doctors prescribed tincture of opium (a liquid anti-diarhea treatment that has been used successfully for many years) as nothing else seemed to work. That has been the most reliable, dependable treatment I've had. I can travel and go out without fears of diarhea attacks. The one drawback, and the reason doctors are hesitant to prescribe it--it's potentially addictive as it contains a small amout of narcotic drug. My doctor has said it's extremely unlikely to become addicted to it. And the benefits seem to far outway the slight risk. But what works for one person may not work for another. The antidepressants may help, as they increase the seratonin level in the brain. I would think it highly unlikely that antidepressants alone can relieve the IBS symptoms. At best, they may be helpful, along with other treatments. Or they may be totally useless like in my case.By the way, Effexor probably gave me the worse side effects of the antidepressants I took, making my mind very spacy. The trycliclics all made me drousy. Prozac caused severe stomach upset. The one best tolerated by me was Wellbutrin. I've heard others have good luck with Celexa as far as minimal side effects.By all means, see a GI doctor who has experience treating IBS, and is willing to work patiently with you to relieve your symptoms. If your doctor even tells you "there's not much else I can do for you--you have to learn to live with this"--get a new doctor. ---Rich