<human>: I've heard that some people get a stomach ache after drinking milk. Is that true?
<bot>: Yes, it is true. Some people can experience symptoms like nausea or vomiting when they drink milk. It’s called lactose intolerance and it’s caused by a lack of the enzyme lactase which breaks down the sugar in milk. This means that the body cannot properly digest the sugar in milk. Symptoms usually improve with age but can persist into adulthood.