Hey, sorry for the late response, and I hope you still get this. Frequent urination, and an unquenchable thirst, are the 2 biggest sign's of diabeties type 1. When I was diagnosed, I went to the washroom once an hour, and I would drink 6-7 cups of water every 2 hours. And still be thirsty. I also was never hungry, and went 3-4 days without eating.

Get a blood test done on him as soon as possible, just to be sure, cause if it is diabeties, and u leave it untreated, it can lead to very bad results. Such as a diabetic coma.