Suggest Treatment For Stomach Pain With Watery Stool

My stomach has been hurting me since Sunday night, it is now currently Wednesday night and it still hurts. I have constant pain, sometimes really dull and sometimes excruciatingly sharp and unbearable. When I go to stool, sometimes it doesn't come out, despite the pain or despite the feeling I have that I want to poop. When I do pass stool, it comes out really loose and watery. It also feels as if there is a constant gas bubble in my stomach. What could be the issue?