What Causes Mental Distraction In A Child While On Adderall?

Hi my 5 year old son is taking 5mg adderalll time releese and has sad soft stool foe about 2 weeks and now his meds seem to not be working i mean he can not focus ,write just busy i was thinking to wait till his stool get back to normal are just see if i can get the dose higher he is driving me crazy.