Can't keep food in my body. after every meal, i end up running to the bathroom in pain, and its very loose. and there is a lot of mucus in my stool.

Stool urgency: If this is an acute problem, it is most likely due to an infectious cause, most of which resolve spontaneously it a few days. If it is a long-term problem, though, you may have irritable bowel syndrome. If so, try increasing your fiber intake, along with extra fluids. If this doesn't work, or if it is an acute problem which does not go away in a few days, see your physician. Good luck.