Do you often feel bloated and suffer from awful stomach pain that has you doubled over after meals? If you spend more time in the bathroom after eating than the average Joe, you may be one of the many people afflicted with lactose intolerance. 

Those who suffer from severe lactose intolerance are unable to digest the sugar found in milk and other dairy products properly. This intolerance is the result of a deficiency of the enzyme lactase. Lactase breaks down the sugar into a simpler, more digestible form. According to the National Digestive Diseases Information Clearinghouse (NDDIC), most people who have lactase deficiency can tolerate some lactose in their diet without too much discomfort. 

As much as 30 percent of the population suffers from lactose intolerance. According to a review published in the European Review for Medical and Pharmacological Sciences in 2013, the authors estimated that about 75 percent of the population experiences the impaired ability to digest lactose at some point in their lives. Symptoms may not appear every time dairy products are consumed.