What Causes Lactose Intolerance in Adults? Before heading out for a day adventure on the Mooresville Ale Trail and sampling all the scrumptious cheeses that sometimes make your stomach hurt read below to put your mind, and your stomach, at ease. Lactose intolerance, characterized by digestive discomfort after consuming dairy products, is a common condition affecting millions of adults worldwide. While lactose intolerance can develop at any stage of life, adults often find themselves grappling ...