For CBT a large-scale clinical trial that should provide numbers good enough for anyone (based on size and design of study) may be out soon.The trial is just now wrapping up (some people still in the one-year follow up period).Study had 4 groups. Antidepressant, Placebo, CBT, Sham Therapy (get attention, come in once a week , get info, but no CBT).Tests were run pre and post (ballon in the rectum for how well you tolerate expansion of the rectum--which tends to be abnormal in IBSers) Symptoms were tracked both during the study and every 3 months in follow up.The CBT will be compared to the drug treatment to see how it faired against it.Now I did the study (CBT part) in 1998, and they just finshed up. With therapy studies it can take a long time because of limited # of hours/week you have the therapist you can only do so many concurrently .One other comment. Most of the DRUGS used for treating IBS also tend to fair badly in these kinds of "what good research do we have" review studies as well. So the evidence for ANY IBS treatment tends to be less then stellar, mostly because most drugs used for IBS are "off-label" uses and they were never initially developed for IBS, and "off-label" uses of pretty much all drugs are really spotty when it comes to how good the data really is.K.