Food intolerance or Digestive issues.

Hi doctor, I have been having gastric issues for last 5 years. Initially I had incomplete bowel evacuations, severe bloating and flatulence. I had abdomen CT and colonoscopy with no issues found. And was told it could be IBS. One year later I realised that I am not able to digest many foods, I had endoscopy and was detected with ulcers. At the same time i had intestinal biopsy and stool test and no proof of food intolerance found. I started avoiding gluten foods and lactose foods and many other foods which made me feel much better. And now the situation is I'm not able to digest many foods (Experiencing bloating and flatulence) and looks like the list goes on increasing because of which I feel like my body lacks nutrition. Pls help.