Lactose is a sugar found in milk, composed of glucose and galactose.
What is lactose intolerance? Lactose intolerance occurs if your digestive system is lack of the enzyme lactase, which break lactose into glucose and galactose. If lactose is not broken down in the small intestine, then it is fermented in the large intestine by bacteria. Fermentation releases gases and causes bloating symptoms.
Symptoms of lactose intolerance:
Abdominal bloating and cramps
What can you do if you have lactose intolerance?
Avoid lactose-based food sources such as milk. And substitute dairy milk with alternative such as soy milk and almond milk.
Take digestive enzyme particularly lactase such as Lactaid
It is still important to have your daily calcium requirement fulfill even you have lactose intolerance.
More information, please refer to http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001321/