Gas...?

Stephanie
I'm pretty sure I'm not the only one who gets this but.. 
Every so often I get really bad pain in my lower abdomen . I have always called it bubbles , pretty sure it's gas, but it gets so painful I can't function for a minute or so and have to sit down and let it pass, only for it to come back again. 
Anybody got any advice on what I can do or what it is that's causing the pain?