Hi , I can't say why you might be having trouble with these foods post surgery, but dairy can be hard to digest for lots of folks with or without endo. I've been vegan for 23 years, but I always got diarrhea, cramping, bloating, and painful gas when I ate dairy.
While I've never heard of surgery bringing on lactose intolerance, your stomach/gut might be a little more sensitive during recovery. I know I always feel a little off the first couple weeks after surgery and tend to gravitate toward bland foods during this time.
The good news is there are tons of dairy-free options out there for everything, including milk, cheese, and ice cream! You could also try something like Lactaid to see if that helps you digest these foods a little better. And definitely bring up the nausea/vomiting with your doctor! - Keri (team member)