My son has suddenly started vomiting over the past 4 days and runny poo. At first I thought possibly gastro but now thinking intolerance to milk/ lactose. I gave yogurt and he vomited half an hour later. Same with his milk but fine with anything else
Up until a week ago he could tolerate his milk so I am just unsure.
Any advice? He is 2.5 years old. Is it possible to suddenly become lactose intolerant? Not sure what to do.. thanks