I have had this problem for a while now.....when riding on a hot day during the first 8 miles of the ride, after a hard hill climb, I get this awful cramping in my lower tummy. It feels as though my uterus is cramping. If I do not stop it just gets worse. I don't this every time I ride, it seems just on hot days. To relieve it, I stop and do a power shot gel and drink some water, then I get on and try to ride through the pain. It usually goes away, but then I feel wiped out. Is this a hydration issue or what. I have talked to my dr. about it and she just looks at me funny. Thanks for any help. Diane