Hi! Almost 2 Years I Had An EGD Done Due

Hi! Almost 2 years I had an EGD done due to chronic indigestion and acid reflux. Shortly after that my doctor recommended that I have my gall bladder out, which I did, and also put me on prescription Prilosec. However, since the surgery after I eat I almost immediately get an upset stomach and need to have a bowel movement. I can have as many as three or four a day. I haven't been able to pinpoint the foods that cause this because I usually eat a combination of foods such as a green salad, sandwich, hamburger or pizza, etc. Can you please tell me what foods I should avoid? This is getting very old.