Doodh not so cool!

Lactose intolerance, a phrase that is being bandied about a lot more these days than during the times of our parents, is basically intolerance to lactose (the sugar that is present only in milk and some processed foods).

Under normal circumstances, lactose is digested by an enzyme known as lactase produced by the most superficial lining of the small intestine, to be broken down to simple sugars, which are then readily absorbed into the blood. It is the deficiency of this enzyme that leads to lactose intolerance.In small infants and young children, this may result in persistent diarrhoea after an attack of gastroenteritis. Related stools are typically watery, frothy and acidic causing redness over the buttocks and areas around the anus, also causing bloating of the abdomen, gas production, general discomfort and weight loss. In older children, gas production causing crampy abdominal pain is the dominant problem rather than diarrhoea itself.

Due to the inadequate breakdown, in the small intestines, the sugar accumulates and the excess sugar (lactose) draws water into the intestine resulting in diarrhoea and /or crampy abdominal bloating and pain. Acids and hydrogen gasses are produced which result in irritation of the skin around the anus accompanied by frothy stools.

Causes of lactose intolerance

Normally lactase levels are highest at birth (to suit milk intake) and start to fall gradually from the age of three years. Also, the levels are at best marginal which are just enough to digest milk in the early years of life. Hence a variety of conditions like gastroenteritis, malnutrition, drugs, milk protein allergy etc can cause harm to the superficial lining of the intestine resulting in temporary deficiency of the enzyme. This leads to persistent diarrhoea even when the infection is under control. Within a few days to weeks, the superficial lining regenerates and the enzymes are restored and the symptoms disappear. Very rarely the enzyme levels are deficient by birth.

Diagnosis

Is done by detection of acidic stools while the child is still on milk diet. Also cessation of diarrhoea upon withdrawal of milk suggests lactose intolerance.

Treatment

• A large majority of infants and children have a temporary lactose intolerance following an infection. Symptoms usually subside when the child is kept on a low lactose or a lactose free diet. If the symptoms do not subside the diagnosis of lactose intolerance should be doubted as a cause of persistent diarrhoea.
• Breast-feeding should be continued as most infants continue to thrive even when passing abnormal stools for a few days after an infection.
• Total elimination of milk is not required routinely. Also milk should not be diluted with water as it reduces the energy levels of the diet .It is better to substitute a part of the milk feeds by diets based on milk with cereals (e.g. milk or curd rice gruel. milk sooji gruel or dalia) or diets based on lactose free milk protein (casein), oil, sugar, soyabean etc.
• In older children and adults, milk elimination should not be total. Stopping milk ingestion as a beverage is important. In such patients, lactose in milk with a meal is better tolerated than alone milk. Lactose intolerant adults may continue to have milk and milk products in small amounts.
• A lactase preparation (lactrase, not available in India) when added to milk or when taken with a milk-based diet may even prove to be helpful.