Suggest Treatment For Irritable Bowel Syndrome

For the last 3 years, I have had problems with nausea, some constipation, but mostly diarehea. It has gotten to the point that I am very weak, dehydrated, and so tired that I am in bed most of the time. I have seen 2 doctors and have had many test including the radioactive eggs. Two years ago I lost my hair and now it is finally growing back. When I even look at food, I feel sick. Both of my previous doctors say I have IBS. The last one said it was from nerves. I think this is a cop out answer. What would you suggest I do. One of the x-ray techs said to take probiotics or maybe I have extra scar tissue do to previous surgeries.