Lactose intolerance is a common condition affecting over 30 million American adults. It occurs when the body lacks enough of the enzyme lactase to properly digest lactose, the main carbohydrate found in dairy products. The undigested lactose passes through the intestines, causing uncomfortable symptoms like gas, bloating, and diarrhea. While complete avoidance of dairy is not necessary for most with lactose intolerance, recognizing the signs can help identify trigger foods and determine optimal daily limits. This article covers the common signs and symptoms of lactose intolerance.

Abdominal Pain and Cramping

Eating the right foods can significantly improve your health. This is especially true for people who have intolerances and allergies; however, very few people know the signs to look out for. One of the most common complaints with lactose intolerance is abdominal pain and cramps after consuming dairy products. This occurs as the undigested lactose ferments in the colon, producing gas that can trigger painful cramping and bloating. The pain is usually felt in the lower abdomen but can radiate throughout the intestinal tract. The severity of the cramps can range from mild discomfort to severe pain that doubles a person over. Sometimes, the pain is accompanied by loud gurgling noises from the intestines. The cramps typically begin 30 minutes to 2 hours after eating or drinking dairy products.

Diarrhea

Another classic symptom of lactose intolerance is diarrhea, which begins shortly after consuming lactose-containing foods. As the undigested lactose moves through the intestines, it pulls water into the colon through osmosis. This causes the intestines to secrete loose, watery stools, resulting in diarrhea. 

Gas and Bloating

Excessive gas production is also a tell-tale sign of lactose malabsorption. The undigested lactose ferments in the colon, releasing hydrogen, methane, and carbon dioxide gases that can lead to bloating, burping, and flatulence. The gas builds up, causing uncomfortable fullness, pressure, or tightness in the abdomen. 

Nausea and Vomiting

Some individuals with lactose intolerance experience nausea and vomiting after eating dairy foods. The nausea is likely triggered by the intestinal cramps, pain, and distension caused by the undigested lactose. In some cases, the vomiting occurs because the high levels of gas buildup displace the stomach contents. Nausea and vomiting are more common signs in children with lactose intolerance.

Fatigue and Lethargy

Feeling tired, unmotivated, and sluggish is another potential symptom, as intestinal discomfort and diarrhea can take a toll on the body. The inflammatory response and nutrient malabsorption caused by lactose intolerance can leave a person feeling drained and weak. Dehydration from diarrhea also contributes to exhaustion in some cases. The fatigue often sets in a few hours after consuming the problem dairy foods.

Recognizing the common signs and symptoms of lactose intolerance can pave the way for identifying trigger foods and customizing your dairy intake. Keeping a food diary and tracking symptoms are useful ways to pinpoint your personal tolerance levels. With the proper dietary modifications, most people with lactose intolerance can still enjoy dairy in moderation.