Why is it that when we laugh so hard, our stomachs hurt?  

Thanks for the nice response, so it has something to do with the muscles, a follow up question, if it has something to do with the muscles, do the people who build up their abs still hurt their stomach when laughing?

I think that they would. The way I understand it is that their are tiny muscles located in the stomach that we normally don't use that often. When we do it makes them ache. I know when I have had one of those laughing fits then sometimes the next day my stomach hurts a little on certain movements..

hahaha, so laughing can make us lose certain pounds, I ought to laugh more haha

Hey there you go..I wasn't thinking about it that way but yeah. Im going to start laughing more too. I have an ideal lets do the laughing exercise every other day and see what happens...LOL..Have a great day kafueenu...

Have a great day too hahaha, I really should loose some pounds, i'm getting flabby haha

I know what you are saying. Im in that chubbing stage too...No really I have been in that chubby stage for years. Continue to have a nice day..

to be more specific, laughing uses intercostal miscles [ribcage muscles], abdominal muscles and diaphragm... and if you laugh continuously for a long period of time these muscles do not get a chance to relax and lactic acid starts building up in them inducing pain. :)

There it is more detailed than anything that I could have said. Thanks
Have a nice evening..

Oh! Your answer is really technical, so we can also relax by laughing haha. Good therapeutic effect. But my nose is bleeding right now, too much technical medical terms haha, just joking. Thank you for the response Binthu