What does lactose intolerance mean?
People with lactose intolerance are unable to fully digest the sugar (lactose) in milk. As a result, they have diarrhea, gas and bloating after eating or drinking dairy products.
The condition, which is also called lactose malabsorption, is usually harmless, but its symptoms can be uncomfortable.
Too little of an enzyme produced in your small intestine (lactase) is usually responsible for lactose intolerance. You can have low levels of lactase and still be able to digest milk products. But if your levels are too low you become lactose intolerant, leading to symptoms after you eat or drink dairy.
The most effective method of managing the condition is to avoid dairy products.
Symptoms
The signs and symptoms of lactose intolerance usually begin from 30 minutes to two hours after eating or drinking foods that contain lactose.
Common signs and symptoms include:
- Diarrhea
- Nausea, and sometimes, vomiting
- Stomach cramps
- Bloating
- Gas
Causes
Lactose intolerance occurs when your small intestine doesn't produce enough of an enzyme (lactase) to digest milk sugar (lactose).
Normally, lactase turns milk sugar into two simple sugars — glucose and galactose — which are absorbed into the bloodstream through the intestinal lining.
If you're lactase deficient, lactose in your food moves into the colon instead of being processed and absorbed. In the colon, normal bacteria interact with undigested lactose, causing the signs and symptoms of lactose intolerance.
There are three types of lactose intolerance. Different factors cause the lactase deficiency underlying each type: Primary lactose intolerance, secondary lactose intolerance, congenital or developmental lactose intolerance.
Source:
https://www.mayoclinic.org/diseases-conditions/lactose-intolerance/symptoms-causes/syc-20374232
