If your baby can't digest lactose -- the main sugar in milk and dairy products -- he is suffering from a condition called lactose intolerance that affects up to 50 million Americans, according to the Baby Center website. Premature babies are more likely than full-term infants to deal with lactose intolerance, the National Digestive Diseases Information Clearinghouse reports, because premature infants may have lower levels of lactase -- the enzyme that helps the body digest lactose.
Genetics
Your infant's genetic makeup may influence whether or not she suffers from lactose intolerance. The National Digestive Diseases Information Clearinghouse says that researchers have discovered that lactase deficiency, which leads to lactose intolerance, has a genetic link. About 90 percent of Asian Americans suffer from lactose intolerance, says Baby Center, and nearly 75 percent of Americans of African, Jewish, Hispanic and Native American heritage do as well. Among Caucasian people of northern European descent, the rate of lactose intolerance is about 15 percent, Baby Center says.
Medications
Lactose intolerance may be a side effect of a medication your infant takes. Some medications may temporarily cause an infant's body to stop producing enough lactase, causing lactose intolerance, reports Baby Center. Chemotherapy medications may hinder the body's ability to produce lactase, the National Digestive Diseases Information Clearinghouse reports.
Intestinal Injury
If something injures your baby's intestinal track, he may suffer lactose intolerance as a result. A severe case of diarrhea may cause lactose intolerance temporarily in your baby's body before he recovers completely within a week or two. That's because severe diarrhea may temporarily damage your infant's small intestine, the National Digestive Diseases Information Clearinghouse says. If your baby suffers from a chronic intestinal disease such as Crohn's disease or celiac disease, those conditions can also damage your infant's intestines, causing lactose intolerance, according to the National Digestive Diseases Information Clearinghouse.
