Will Lactose Intolerance Cause Diarrhea?

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.

How long does lactose intolerance diarrhea last?

Symptoms of lactose intolerance usually begin between 30 minutes and 2 hours after consuming dairy. The symptoms last until the lactose passes through your digestive system, up to about 48 hours later. The severity of your symptoms can be mild or severe depending on how much dairy you eat.

Can lactose intolerance cause watery diarrhea?

Summary Lactose intolerance can cause diarrhea, or an increase in the frequency, liquidity or volume of stool. It occurs when undigested lactose ferments in the colon, producing short-chain fatty acids that increase the amount of water in the gut.