Contraction like cramps after food intake, yellow diarrhea stool for 2yrs which smells extremely like vomit. what could it be?

IBD: With that long a history of these symptoms, you need to have an examination and some stool studies, blood tests, and a colonoscopy at the very least to determine the reason for your symptoms. I would be suspicious of an Inflammatory Bowel Disease like Crohn's or Ulcerative Colitis but could also be a chronic infection or irritable bowel disease. Get checked!!!