Sudden diarrhoea!

Nisha

My 10 month old Son has diarrhoea for the last two days but no fever. Because of the loose stools he has a bad diaper rash. Everytime he feeds, he has the urge to pee/poo. I am making sure he is hydrated. How long should I wait to see if it settles before going to the doctor? Advice please! Could it be linked to his teething?