But for some people, this process is accelerated. They eventually begin to suffer symptoms every time they drink milk or eat certain kinds of dairy products. Lactase deficiency is also associated with some types of digestive disease. It can also develop following an injury to the small intestine. Rarely, infants are born without any ability to produce lactase at all.
Lactose intolerance is also more common among certain ethnic groups.
From time to time, almost anyone may experience a temporary bout of lactose intolerance. This means that your body tends to produce only as much lactase as needed. Even those who produce normal levels of lactase will become deficient if they stop drinking milk for an extended period of time. When they start drinking milk again, they may experience symptoms of lactose intolerance until their body once again produces a sufficient quantity of lactase. Several tests are available to help doctors diagnose lactose intolerance.