why cant I drink?

[supercooper]

I know this may sound stupid but weather I ride 5 miles or 50 miles I cant drink because it gives me stomach cramps. When I finish my ride I am fine but during is a big no no , Even if I just take a little sip , I make my own energy drink which is just per 1 ltr of water - 4 tblsp glucose powder - 1 tsp salt and natural dilute juice taste . But even just water gives me cramps , I know you need to re-hydrate but just cant do it . Any ideas :?: :?: :?:

 

[HLaB]

Try Pre Hydrating before a ride and that way you are just topping up on a ride and hopefully it'll go down easier but you maybe are already doing that.