Amanda, I've had lactose intolerance since I was about 12 and it has gotten worse as I've aged. I have never been diagnosed and haven't felt the need to. I have all the symptoms and I can solve the problem by just not drinking/eating milk and certain other dairy products. The milk products that one is most sensitive to can vary for different people, so you will figure that out by trial and error. I haven't had a glass of milk for over 20 years and do not miss it. It never tasted good to me anyway. Other foods I cannot eat: cream (al fredo sauces are deadly!), soft cheeses including ricotta and cream cheese (am fine with hard, aged cheeses like cheddar), mass market yogurt (I can't eat the cheap brands as they have powdered milk added to them to thicken the texture but I can eat the more "natural" or authentic ones that don't contain milk powder), ice cream to some extent (I eat little bits of it now and again).

I have never tried the lactaid pills as it is not too hard to have a balanced diet by avoiding the dairy products that upset my stomach. And since I don't like the taste of milk, that makes it even easier.

Popcorn: I have never heard of that! Plain popcorn has no dairy in it. Maybe the person sensitive to popcorn was putting some kind of topping on it or eating that packaged microwave stuff with the flavorings? I can see that might possibly contain some lactose. Or maybe the popcorn sensitivity was unrelated to the lactose intolerance. I wonder if the person was also sensitive to fresh corn?