Hello, I'm a 16 y.o. 145 lbs cross country runner. I've been running for about 2 years now, and ever since I've started running seriously (varsity) I've been experiencing stomach problems while racing. After about 10 minutes of hard running, my stomach cramps up severely and it makes it extremely difficult to keep the pace. I've tried not eating 4+ hours before a race, and avoiding any dairy products for a day before a race, but it doesn't seem to help.
My fellow runners do not seem to have this problem often, let alone every single race, so I know something's abnormal here. I do have a fairly sensitive GI tract, but I don't know what I'm supposed to do about it.