My son is 7 in August and has been clean since 2 years old. The last few months he has been soiling his underwear/pyjamas initially infrequently but this lady few weeks it is becoming more common.... We have had 3 incidences today ( it isnt usually everyday).
He isn't constipated, he has fruit/veg/salad, is active, drinks lots and fluid.
It is possibly unrelated but he has had bad hay fever this year is currently on daily anti-histamines and inhalers.