Years ago when marathoning, gels could set my intestines off, but more recently running itself seems frequently to trigger an upset tummy. There doesn't seem to be an obvious correlation with what or when I've eaten. I've tried immodium and this sometimes works but not always. The problem is so regular now that I am very glad I have given up serious racing. I am even reluctant to run in company in case my stomach starts griping. Intestinal cramps sometimes continue for several hours after a run.
I am on the point of going to my GP to check if there is any underlying problem, but thought I would first ask on here if there are any fellow sufferers or if anyone can offer advice?