For about a year and a half I was having very thin stools and bloating. I went to the Dr. and he did a FOBT that came back negative. Since I am only 36 and in pretty good shape with no history of cancer in family he said that I should try a bulk forming laxative like Metamucil. I did and within a day or two my stools were bigger than ever. I was very glad to see this but also in those first couple of days I was having reasonably sharp pains on my left side. They went away after a day or two. I recently went on a weekend trip and forgot to bring my Metamucil. Like clockwork, I started having thin stools again. When I started back up on the fiber, I again got the pain in my side. My guess is that my colon is very constricted like a muscle that is flexed and that the extra bulk is forcing it to widen out. This forced widening is the source of pain. Since the pain goes away after about 24 hours, I have not worried too much about it. Does anyone have any alternative theories as to why I have this pain?

Thanks