You can try Beano for gas. Swallow 2-3 pills before eating. If the cramps are in your stomach rather than your abdomen, you need to see your doctor. Abdominal cramps usually are related to gas or stool in the bowel. Stomach pain is another matter and could indicate an ulcer that will require antibiotics and a stronger dose of Prilosec to clear. For abdominal cramps, exercise is also helpful as is getting plenty of water.
Stool softener or a mild laxative may get your bowels moving again. Be sure to drink lots of liquid. Prune juice, if you can drink it, is an old stand-by for constipation. If you can't move your bowels and the pain continues tomorrow you should see your doctor.