Is it lactose intolerance? Because that's a weak argument. Lactose can be broken down in the gut in one of two ways, for the lactose tolerant, this is through an enzyme called lactase, which you create in your gut naturally. It separates the lactose into smaller parts that can be digested normally.

For the lactose intolerant, they lack (or at least underproduce) lactase in the gut, so the breakdown of lactose to its more basic chains is done through fermentation (or something similar), which produces significant amounts of methane gas. That extra pressure in the gut causes your body to flood the area with whatever water it can, which creates the unpleasant experience associated with lactose for the intolerant.

But get this... Science has found a way to package lactase into a pill that you can take. I know right? Mind blown. So you take the pills before or during your lactose filled meal and... You're fine. Amazing!

Science.