1yr old hates milk

My son just turned 1 yr a month ago and so far when I have let him try dairy products he would get diarrhea. The only thing he can really tolerate is cheese. His pediatrician recommended trying organic milk but that also gave him diarrhea. I tried lactaid and got him to drink about 2 oz and no diarrhea, he just hates the taste of regular milk so much and he is too smart 😂 if he knows there is milk in the cup he will pitch a fit and refuse it. Im at a loss. Just wondering what kind of advice is out there from other parents facing the same issue. Thanks in advance!!