Any mamas have kids with this issue.. what was it.. my son sence he was born has had an issue with runny poo/ diareah...…

Any mamas have kids with this issue.. what was it.. my son sence he was born has had an issue with runny poo/ diareah... we had to buy the expedite formula for him and have noticed he has a milk allergy.. so we cut out milk and give him flavored water and he still gets diareah.. im at a loss on what's going on... also he's 2 I do plan on calling doctor to see if we can do an allergy test