Why do I always get a horrible stomach ache after eating beef? Lately everytime I have either hamburger or steak for dinner I get a very sharp pain in the middle of my stomach that lasts for hours. I stopped eating beef altogether & the stomach ache has stopped. I have spoken to my family doctor about this issue & they have done blood work and nothing was wrong. Cholesterol was fine, blood pressure was fine, glucose was in good condition. What could it be?