Uncommon tests include a biopsy from the small intestine (a sample is collected and analyzed in the lab) or a genetic test.

Lactose intolerance usually occurs due to genetic defect or reduced activity of the enzyme lactase with age. This is the main reason, why there is no way to prevent lactose intolerance.

"Babies do not develop lactose intolerance until they are 3 to 5 years old. The intestinal lactase remains high in all infants, except the very rare situation where there is a genetic lack of the ...

But sometimes, these levels of lactase naturally decline, either due to genetics, age ... of the world's population is considered lactose intolerant, she adds. The severity of intolerance ...

Are you lactose intolerant? Many people are ... In fact, researchers have identified many genetic loci at which selection has likely occurred, and some of the selective pressures involved have ...

Gas, bloating, pain, that kind of thing when she would eat ice cream or cheese or drink regular milk Narrator It's unusual for lactose intolerance to develop before age two – it's typically ...