Question:
Our 13-year-old daughter has developed an intolerance for drinking milk since being on large doses of antibiotics. However, she can eat yogurt and some ice cream. If she takes Lactaid she has occasionally vomited. Why would this happen? And why can she apparently tolerate lactose in some dairy foods but not others?
Answer:
Some people don't do well when they drink milk because they don't make enough of an enzyme called "lactase," which is very important for breaking down lactose sugars found in milk, ice cream, cheese, and other dairy products. When this happens, a person who eats these things may feel cramping (achiness), bloating (feeling filled up), flatulence (lots of gas), and vomiting.
Lactose intolerance is usually inherited, but surgery, infectious diseases, and drugs that may damage the intestines can also cause it. In such cases, lactose intolerance should go away once the intestines heal. Please check with your pediatrician about whether or not the large doses of antibiotics your daughter took might be affecting her digestive system.
Lactaid doesn't always work that well for everyone, especially since it might also not be the lactose that is the problem. If your daughter also has hives, rashes, swelling, wheezing, itching, or vomiting when drinking milk, this may mean she has developed an allergy to a protein in milk — something different than lactose intolerance. If milk allergy is the problem, Lactaid won't help.
Assuming that your daughter is lactose intolerant, it's important to know that each person handles this condition differently. For example, those who have more lactase enzymes in their bodies may be able to drink more milk than those with fewer lactase enzymes. Because milk generally has a greater amount of lactose, people with a lower number of lactase enzymes might be better off with ice creams, yogurts, creams, and other dairy products that have less lactose in them. Perhaps this is why your daughter can tolerate some foods, but not others.
