Question about lactose intolerance?

So I've been having some digestion problems the last few days and I've narrowed it down to two things. Lactose and gluten. Celiac disease runs in my family but I don't want it. So how can I test if its lactose intolerance without getting the same digestion problems? Or am I just gonna have to chug a glass of milk and deal with it if it is lactose that's causing it?