Stop in for a cup of coffee

Do any of you guys have issues with Lactose? Reason I ask is I've noticed the old I have gotten the more it messes with me. I drink a big glass of milk with dinner every night sometimes 2. Usually never an issue. Last night I had a big bowl of ice cream and it destroyed my stomach. The night before I had a bowl as well and no problems at all. Its just odd, that sometimes it affects me and other times not at all. So curious do any of you have similar issues?