I have IBS M (Mixed) and have had it for about 8 years. I tried the diet they recommend but it was much too difficult for me. I know what some of the food offenders are, but not always. I fluctuate between having constipation (impactions) and terrible diarrhea -- on the same day.
Yesterday, I felt like I had to have a BM (not an emergency) and could NOT believe how I had totally soiled myself; one of the worst messes in my life (in my 90's now). UNREAL. So I was very careful with food all day and ate very little -- toast, one scrambled egg, one very weak coffee (instant) which I sometimes take when I NEED to have a BM. That was yesterday.
Today (30 minutes ago) I felt as if I had to have an BM (again, no emergency) and was SHOCKED to see that the toilet bowl was full of diarrhea/pieces of stool -- all sizes/shapes. I went online to see if possibly they had found some medication for this terrible syndrome and saw they had a new one Public Citizen in August 2000 petitioned the FDA to remove the drug because of evidence that it caused ischemic colitis, a life-threatening condition in which bowel tissue dies as a result of a lack of blood flow to the colon. Many patients were hospitalized and suffered permanent injuries shortly after the "new" drug was introduced. Many patients had severe reactions and a few died! SO MUCH FOR MEDICATION.

Why was Alosetron taken off the market?
Public Citizen in August 2000 petitioned the FDA to remove the drug because of evidence that it caused ischemic colitis, a life-threatening condition in which bowel tissue dies as a result of a lack of blood flow to the colon. Many patients were hospitalized and suffered permanent injuries.

What are we supposed to do? I have a great gastroenterologist. He knows his topic but he tells me he cannot help me. I know what I eat and I know what I need to do. I don't.

Good luck to all of you.