Stomach pains

I’ve been having really bad pains in my bowels/ gut, to the point at evening I’m in such discomfort. It’s fine at the start of the day but its sore and uncomfortable at the end of exercising and the day. I’ve been under a lot of stress lately and will be for the next two weeks. What can I do to relieve it a bit? Have I eaten something I’m allergic to? It feels swollen and inflamed, I’m really hoping it’s just something I ate and will go away in a few days