Hate to tell you this, but that's the way most doctors are on the subject of IBS. I had major battles with several dr.'s before I finally got two to finally listen to what I was saying. And, I was right. The fiber is a great way to go. I would still suggest the colonoscopy. Also, elimiate all wheat, rye, barley and oat products just to see if it gets better. That includes beer, whiskey and most alcohols from distilled grain. And, believe it or not, anything with distilled white vinegar, ie. pickles, capers, peppers, picante sauce, etc. Just give it a try and see if your symptoms ease. Can't hurt a thing! Good Luck!