The most common cause of diarrhea after ingesting milk is lactose intolerance. Individuals who suffer from lactose intolerance are missing an enzyme that properly digests dairy products, leading to uncomfortable digestive symptoms. Symptoms of lactose intolerance include diarrhea, bloating, constipation and stomach cramps.
While milk is the strongest culprit when it comes to lactose intolerance, dairy products such as cheese, yogurt and ice cream are also known to cause stomach discomfort. Ice cream and hard cheeses can trigger constipation, and yogurt containing milk fat also causes diarrhea.
Diarrhea caused by lactose intolerance is easily controlled by diet and enzyme supplements. Taking one to two enzyme supplements prior to drinking milk helps the digestive system digest the lactose, in turn eliminating symptoms of stomach discomfort and diarrhea. In addition to taking enzymes, individuals who suffer from diarrhea following milk ingestion can opt for lactose-free milk and dairy products.
While lactose intolerance is the most common cause of digestive discomfort following milk or dairy product ingestion, diarrhea is also a symptom of stomach flu, food poisoning and serious stomach disorders that include ulcerative colitis and colon cancer. If eliminating diary from the diet or taking enzyme supplements do not control the symptoms of diarrhea, it is important to consult with a health professional for complete medical testing.