I am in my mid 30's, moved to US from India a few years back, after lot of suffering, visit to Urgent care, Colonoscopy and lot trial and error I found out it was the milk which was causing the issue, currently I consume low fat lactose free milk and non fat greek yogurt from Costco.

one question I keep wondering about is, do I have lactose intolerance or issue with digesting milk fat from cow milk. I am able to consume all products with any amount of fat content made from Buffalo milk inlcuding lactose (Buffalo milk is predominantly used in India)