Lactase is an enzyme produced in the small intestine that helps break down lactose, a sugar found in milk and dairy products. People who have enough lactase can easily digest these foods, while those with low levels may experience discomfort, a condition known as lactose intolerance. When lactose is not properly digested, it can lead to symptoms like bloating, gas, and diarrhea. Many individuals with lactose intolerance can manage their symptoms by consuming lactose-free products or taking lactase supplements to aid digestion.