Allergy to Milk

An allergy to milk is known as lactose intolerance. Those affected with the allergy will have an inability to digest or absorb lactose, which is the sugar in milk. When products containing milk are eaten or drunk then certain gastrointestinal symptoms will appear due to this intolerance.

The Causes of Lactose Intolerance

The sugar lactose is itself made up of glucose and galactose, which are smaller sugars. When lactose begins to be absorbed by the body, it must first split the lactose into these two smaller sugars which can then be absorbed through the cells in the small intestine. Lactase is the enzyme by which the body is able to split the lactose into glucose and galactose. This enzyme is usually present on the surface of these cells in the small intestine.

In the case of those who are lactose intolerant, there is either a reduced level of lactase or reduced activity (also known as lactase deficiency) which prevents the splitting of lactose into the smaller sugars. This either occurs due to congenital reasons, secondary or developmental factors.

The Symptoms of Lactose Intolerance

The most common symptoms of lactose intolerance are gastrointestinal which include diarrhea, abdominal pain, and flatulence. Other less common symptoms include abdominal bloating, nausea or abdominal distention. However, these symptoms may also be caused by other gastrointestinal conditions, so they are not a sure sign that somebody is lactose intolerant.

The reason for these gastrointestinal symptoms is due to the fact that the lactose (unabsorbed) passes straight through the small intestine into the colon. The natural bacterium in the colon is able to split the lactose down into glucose and galactose but this leads to a release of hydrogen gas. Some of the gas is absorbed and released in the breath, but the rest of the gas is used in the colon.

Some of the lactose remains unsplit and causes loose, diarrheal stools. However, the symptoms will always vary from person to person.