I use to get those all the time when i was fat and lazy. im still fat and lazy but i actually do work in gym now, Sometimes i actually watch what i eat :3
but anyways, Tums, lie down. And for me, there is a flash game for everything. When I get stomach aches, I play extreme heli boarding. The music added with simple gameplay brings me into a nostalgic coma, making me forget about all worldly problems.