I'm afraid there's quite a few people on this board with constant gut problems, pain and general suckiness. Hopefully some of the diverticulitis people can give you some hints for avoiding flares and clearing them up afterwards (my stepfather finds he can't eat seeds--like on bread or in certain fruit--because the seeds have a tendency to lodge in his little pocket and cause a flare). I'm not saying that doctors are never wrong, but I think you can be resonably confident that your tests were indeed clear of cancer. IBS and diverticulitis can certainly cause the pain and problems that you are having all by theirselves without any help from something worse. And weight loss isn't that uncommon when people get sick like that; there are a number of people here who have lost weight and who have trouble maintaining a healthy weight because they get sick so often when they eat, so they don't eat and poop too much out to boot. I hate to say "join the club" but... here we are.