Looking for medicines that help IBS, or Crohn's Disease?

I have had bouts of diarrhea, every few months. It would last for a few days to a week. I would take probiotics, fiber, and sometimes an antibiotic. After a week at most things were OK. But over the years, it has gotten worse. From 2-4 times a year to once a month to once a week, until 8 months ago it is almost everyday. Now it seems no matter what I eat it goes right through me, within a few hours. They have tripled my fiber, in the last 3 months and had 2 courses of antibiotics. Still no help. But every drug I see on TV, or look up claims it causes possible liver damage, and a brain infection that could cause my death. Anyone have good luck with any IBS meds they can tell me about.