does anybody know what causes stomach cramps while running and how you can prevent them?

What do you eat before you run?

Was this the first time you've has this problem? If so I wouldn't put to much stock in it. Anyone can have an off day, for myraid reasons...

Before you run try eating something simple like a banana, a plain bagel or oatmeal(my choice). You could even try toast and peanut butter.

Make sure your hydration is good as well.

I get stomach cramps in all types of situations. Can't eat or drink before I run. At least 30 mins before, no drinking water while running. No running down hill. Sometimes for no reason at all and not something I can just keep running and it goes away like leg fatigue. Sigh, I really suck at running. 6 more weeks.

your abs might be weak.

try doing crunches to stregnthen your abs.

don't overload on the H2O and unless you are putting in serious distance, there is no need to eat before a run.

if you run first thing in the AM, run before breakfast.