If a person who is lactose intolerant drinks large amounts of milk in a short time, the lactose reaches the large intestine where it is digested by bacteria. This causes symptoms such as diarrhea and flatulence (gas). What is the cause of lactose intolerance?
Answer: Lactose intolerance is caused by a deficiency of the intestinal enzyme lactase that splits lactose into two smaller sugars, glucose and galactose, and allows lactose to be absorbed from the intestine.
