what is the diagnosis help me plzzzzz......
Posted: 08 Dec 2012, 07:16
Which of the following statements regarding lactose intolerance is correct?
In a hydrogen breath test, after an overnight fast, 25 grams of lactose (in a solution with water) is swallowed. If the lactose cannot be digested, enteric bacteria metabolize it and produce hydrogen, which, along with methane, if produced, can be detected on the patient's breath by a clinical gas chromatograph or compact solid-state detector. The test takes about 2 to 3 hours to complete.
The frequency of decreased lactase activity ranges from 5% in northern Europe through 71% for Sicily to more than 90% in some African and Asian countries.[6] This distribution is now thought to have been caused by recent natural selection favoring lactase persistant individuals in cultures that rely on dairy products.[7] While it was first thought that this would mean that populations in Europe, India, and Africa had high frequencies of lactase persistence because of a particular mutation, it has now been shown that lactase persistence is caused by several independently occurring mutations.
four general principles in dealing with lactose intolerance — avoidance of dietary lactose, substitution to maintain nutrient intake, regulation of calcium intake and use of enzyme substitute.[25]
Lactose is degraded to glucose and galactose by lactase