Lactose intolerance is the inability to digest milk sugar due to a deficiency of lactase, the enzyme needed to break down lactose. According to the National Institutes of Health, symptoms occur as a result of the undigested lactose being fermented by bacteria in the colon. Potential symptoms include abdominal cramps, bloating, gas, nausea and diarrhea and can range from moderate to severe, depending on the amount of lactose consumed and the level of lactase deficiency. While diarrhea is a common symptom, you can still be lactose intolerant without experiencing it.
Diarrhea
Diarrhea means having loose, watery stools at least three times a day. It can lead to dehydration, a loss of fluid and minerals needed for normal body function. According to the National Digestive Diseases Information Clearinghouse website, chronic diarrhea -- continuous or sporadic diarrhea lasting more than four weeks -- is usually due to a functional disorder or intestinal diseases like irritable bowel syndrome, Crohn's Disease or inflammatory bowel disease. However, if you only note diarrhea 30 minutes to two hours after consuming dairy products, it could be caused by lactose intolerance.
Tests and Diagnosis
Your doctor will most likely test for lactose digestion either with a blood test or breath test if you commonly experience any of the gastrointestinal symptoms after consuming dairy, according to the Mayo Clinic website. The blood test measures glucose levels in your blood. If lactose is digested and absorbed, glucose will rise in the blood. The breath test measures production of hydrogen. Little hydrogen is produced normally. However, fermentation by colon bacteria leads to the production of hydrogen and other gases.
Individuals at Risk for Lactose Intolerance
Lactose intolerance is most common in African Americans, Hispanic Americans, American Indians and Asian Americans. According to PubMed Health, individuals may develop lactose intolerance after infections of the small intestine and after bariatric surgery. Tolerance may or may not improve over time. Other individuals who may experience intolerance include individuals with intestinal diseases, such as celiac sprue, and those who have had bowel surgery.
Treatment
Treatment of lactose intolerance generally means decreasing dairy intake or complete avoidance. PubMed Health says that most individuals can tolerate small amounts of dairy, about 2 to 4 oz. Dairy products that generally are tolerated include buttermilk, yogurt and hard, aged cheese because their lactose levels are lower. Individuals can also find dairy products that are lactose-free or lactose-reduced. These products are made from cow's milk with the lactase enzyme added. You may also purchase lactase enzymes that can be added to milk or taken orally.
Considerations
Many individuals assume gastrointestinal distress symptoms are due to lactose intolerance without being tested. However, these symptoms can be caused by many diseases, viruses, infections, disorders or other food sensitivities, says the National Digestive Diseases Information Clearinghouse website. Contact your doctor if you believe you may be lactose intolerant to rule out other causes.
References
- PubMed Health: Lactose Intolerance
- Mayo Clinic: Lactose Intolerance
- National Digestive Diseases Information Clearinghouse: Lactose Intolerance
- National Digestive Diseases Information Clearinghouse: Diarrhea
- "NIH Consensus Development Conference Statement: Lactose Intolerance and Health"; F.J. Suchy, et al.; February 2010
