In "Escape!", one of the "I, Robot" stories, the robotic intelligence in the first FTL spacecraft prototype undergoes certain problems relative to the First Law and reacts to them by displaying eccentric behavior. For example, it only supplies its passengers with canned beans and milk. A diet like that should cause major problems with gas attacks.
I did not understand the joke when I read that story the first time because I am not lactose intolerant and I can drink large quantities of milk without problems. Which makes me think that Asimov might be more familiar with lactose intolerance than I am.
Asimov liked to talk about personal details in the prologues to his stories and his articles about history or science. I remember, for example, when he commented that he was going to undergo a heart operation (in which, according to his biography, he contracted HIV). Did he ever mention a problem with lactose?