What are common symptoms of lactose intolerance?

Lactose intolerance primarily results from the body's inability to adequately digest lactose, the sugar found in milk and dairy products. This condition stems from a deficiency in lactase, the enzyme responsible for breaking down lactose. When lactose is not properly digested, it remains in the intestines, leading to symptoms caused by gas production and fermentation.

The symptoms associated with lactose intolerance commonly include stomach bloating, diarrhea, abdominal cramps, and gas. These gastrointestinal responses occur within a few hours following the consumption of lactose-containing foods. Bloating happens due to the accumulation of gas from the fermentation of undigested lactose by bacteria in the gut, while diarrhea can result from the osmotic effect of the undigested lactose drawing water into the intestines.

In summary, the symptoms of stomach bloating and diarrhea directly relate to the physiological processes involved in lactose intolerance.