A common cause of diarrhea
About the article
This is a digitised version of an article from The Cayman Compass's print archive. Occasionally, the digitisation process introduces transcription errors, or other problems.
See the article in its original context from March 1984.
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Lactase deficiency (the enzyme) can be present at birth or it can develop at a later age. Lactase deficiency is common up to 30% of some population it is high in the American coloured people, Africans, Orientals, native American Indians and some Mediterranean peoples. It can also be present in premature infants and following acute attacks of diarrhea in young infants and children and in patients with certain parasites, irritable bowel problems, inflamation of the bowel and after abdominal surgery, but these are only temporary. It certainly is the commonest cause of non-infective, longstanding diarrhea.
The enzyme lactase breaks down the sugar lactose into the two simpler forms glucose and galactose. This enzyme is present in the lining of the small bowel. Lactose cannot be absorbed through the bowel wall unless it is broken down. Glucose and galactose are easily absorbed through the bowel wall and into the blood stream. If it is not broken down in the small bowel it attracts water by osmosis and they then enter the colon. There are a lot of bacteria normally present in the colon and these act as enzymes to break the lactose down to other simpler forms called monosaccharides, which are fermented into organic acids and gas. This leads to abdominal distention, pain and the passage of gas, and diarrhea. How is the diagnosis made?
Many people in our offices will say that they have noticed that there is a connection between drinking milk or beer, or eating milk products, cheese and icecream and increased gas and diarrhea. However, many people do not make this connection. Anybody, not necessarily a doctor, knowing this possibility can make the tentative diagnosis in themselves or their family and then consult their doctor for a final diagnosis. Half the battle is thinking of the possibility of a lactose intolerance in the first place.
The diagnosis is easily made in those patients with a severe lactase deficiency. The difficulty is with those that have a minor deficiency of the enzyme, since they can tolerate a glass of milk a day or one beer a day.
The problem then results when they have a number of glasses or a great deal of cheese and ice cream.
When the history is not so obvious, the next thing I do for my patients is ask them to drink 4 glasses of milk in one hour. Even a mild lactose intolerance will then be detected in that they have more gas and also some diarrhea soon afterwards. A more exact way of making the diagnosis is a laboratory test in which the patient is asked to drink some lactose and blood tests are taken to see is the blood sugar goes up afterwards. If the enzyme is deficient, the glucose is not absorbed through the gut and into the blood stream and the blood tests for glucose will not rise; this confirms the diagnosis of lactose intolerance.
However, the best test of all is a small intestinal biopsy which does show the decreasedlactase enzyme activity. Another test is a breath exhaling test to measure hydrogen from the unabsorbed lactose; these last two are not used very often. Lactose is present in large amounts in milk, yogurt, soft cheese - not in old and hard cheeses, and in certain prepared foods such as french fries, baby food, party dips, ice cream, puddings and some pie fillings. There are some milk solids present in such dried foods as soups, instant potatoes and breakfast drinks, powered soft drinks and is used as a carrier or vehicle in many tablets and capsules. The symtoms of lactose intolerance can be stopped by excluding these products from the diet.
In cases where the lactose intolerance is only a temporary one following such things as gastroenteritis, one should test again at a later date by slowly introducing milk into the diet to make sure the intolerance is not permanent. For those who really don't want to do without milk, there is a chemical which will break down or pre-digest milk - a commercial lactase preparation. It can be added to a quart of milk, mixed and refrigerated. for 24 hours. It will break down 70% of the lactose. The milk will taste a little bit sweeter and should be drunk quite cold. However, it is excellent to use as an additive to cereals, etc. etc.
In summary, lactase deficiency is a very common cause of abdominal gas and diarrhea - especially in some ethnic groups. It often occurs temporarily after gastroenteritis and surgery. A diet free of milk and dairy products is all that is necessary in most cases. If some people with lactose intolerance really enjoy milk, commercial lactase can be used to treat the milk before drinking. Lactose intolerance is something to think about if you or someone you know has frequent episodes of diarrhea. Your Caymanian Doctor.
