Stomach keeps hurting

This is the second night that I’ve gotten a bad stomach ache/diarrhea after eating dinner. I can’t pinpoint what’s causing it.

Yesterday I ate alot of stuff and ntn but as soon as I ate dinner which was beef ribs, roasted potatoes and broccoli. I had an almost instant stomach ache and had a diarrhea pass twice.

Today I had breakfast which was Raisin Bran crunch cereal and some bacon. Lunch I had a Salad from Wendy’s. Dinner I had a slice of shepherds pie. Again almost instantly after eating dinner I had a stomach ache and diarrhea.