Severe liver problems can, in some cases, cause lactose intolerance, a disorder that occurs when your intestines don't produce an enzyme called lactase. Liver problems can lead to bacterial overgrowth in the small intestine, which could cause lactose intolerance. A medicine called lactulose, which contains lactose and other sugars, decreases the risk of encephalopathy, a type of brain damage, in people with severe liver disease; but it causes symptoms similar to lactose intolerance in 20 percent of people who take it, according to Drugs.com.
Causes of Lactose Intolerance
Cells lining the small intestine produce lactase, an enzyme that breaks down the milk sugar lactose into two other sugars, glucose and galactose. Primary lactose intolerance, an inherited condition, appears after the age of 2. Secondary lactose intolerance can occur after a bout of intestinal flu, if you have disorders that affect the intestine such as irritable bowel syndrome or if you've had stomach surgery. Bowel damage from severe liver disease could cause lactose intolerance.
Small Bowel Bacterial Overgrowth
Liver disease can increase your risk of small bowel or intestinal bacterial overgrowth, called SIBO or SBBO, which can damage the intestines. In a German study reported in the October 2001 issue of "The American Journal of Gastroenterology," researchers found that 61 percent of patients with cirrhosis had SIBO. Another report published by Chinese researchers in the April 2010 issue of "Alimentary Pharmacology and Therapeutics" reported that SIBO increases the incidence of lactose intolerance.
Lactulose and the Liver
If you have severe liver disease, you may take lactulose, a synthetic sugar derived from lactose, to treat hepatic encephalopathy. Lactulose ingestion can cause similar symptoms to lactose intolerance, include bloating, gas, abdominal distention and diarrhea, in some cases. Lactulose pulls ammonia from the blood into the intestine, where it is eliminated in the stool. Ammonia buildup in liver disease can cause confusion, lack of coordination and excessive sleepiness. Lactulose administration can decrease ammonia levels by between 25 and 50 percent in around 75 percent of patients that take it, according to Drugs.com.
Considerations
A person with liver disease can suddenly develop lactose intolerance, which can affect adults at any age, even if they've never experienced symptoms before. The risk of lactose intolerance increases as you age and may not have anything to do with liver disease. Damage to the small intestine could contribute to secondary lactose intolerance, so check with your doctor if you experience the symptoms of lactose intolerance. Taking lactulose could cause symptoms that mimic lactose intolerance.
References
- National Institute of Diabetes and Digestive and Kidney Diseases; Lactose Intolerance; June 2009
- Drugs.com: Lactulose
- "Alimentary Pharmacology and Therapeutics"; Lactose Intolerance in Patients with Chronic Functional Diarrhoea: The Role of Small Intestinal Bacterial Overgrowth; J. Zhao, et al.; April 2010
- "American Journal of Gastroenterology"; Small Intestinal Bacterial Overgroth in Patients with Cirrhosis: Prevalence and Relation with Spontaneous Bacterial Peritonitis; T. Bauer, et al.; October 2001
