Causative & risk factors
Deficiency of an enzyme lactase is responsible for causing lactose intolerance. This enzyme is produced by the small intestine. The function of this enzyme is to break down lactose into glucose and galactose. In the absence of lactase, lactose passes on into the colon (lactose malabsorption) and reacts with the intestinal bacteria producing symptoms.
Lactose intolerance may be congenital or may result due to certain illnesses. Congenital lactose intolerance is a rare inherited disorder in which babies cannot digest lactose since birth.
Lactose intolerance can occur as part of other intestinal diseases like IBS, celiac disease or cystic fibrosis. It can also occur after an acute illness or surgery of the small intestine.
Certain races have a higher probability of developing this disorder. Advancing age can sometimes weaken the capacity to digest lactose leading to primary lactose intolerance.
Clinical presentation
Depending upon the levels of enzyme lactase, the symptoms of lactose intolerance may range from mild to severe. Symptoms occur in response to ingestion of lactose which is found in milk products. The symptoms begin about half hour to 2 hours after intake of lactose containing foodstuffs. Patients complain of rumbling sounds and pain in their abdomen. Gas is produced giving rise to bloating. The person develops diarrhea. Sometimes nausea or vomiting may also occur.
Investigations
Lactose intolerance can be confirmed by carrying out a Lactose tolerance test. In this test, the blood sugar levels of the patient are monitored after giving him a lactose rich liquid. Another alternative is the Hydrogen breath test; in which the hydrogen levels in the patient’s breath are measured after giving him a lactose rich liquid.
A test to measure the acidity levels of stool is used in infants who cannot undergo Lactose tolerance or Hydrogen breath test.
Treatment
Lactose intolerance cannot be cured. Depending upon the severity of the condition, the patient must either cut down or severely limit the intake of dairy products. Regular milk can be substituted with alternatives such as soy milk. Care must be taken to get enough calcium through other food products such as spinach, broccoli, rhubarb and foodstuffs fortified with calcium. Calcium and vitamin D supplements may be given if necessary.
