6 year old ds came home today having had two wetting accidents at school. He had one last week. The teaching assistant I spoke to seems to think he must have a problem as he'd asked to go to the toilet about 90 mins before the last accident. At home , I still have to remind him to go as he will never think to go himself. It also seems to me that he doesn't have a very strong bladder as he needs to go fairly frequently. He also isn't dry at night yet. Should I take him to the doctor? His brother rarely had accidents and could always hold on for long periods and was dry at night from age 3 so I'm thinking this isn't normal?