Child having penis pain..?

So my job was moved to being mostly work at home, so I began watching my niece and nephew. Well I've been watching them for 3 months now and ever since day one my 6 year old nephew is constantly complaining of his 'private hurting'. I've told his mother and she thinks he's a baby and that it just hurts because he holds his pee. But yesterday we were in the store and he was in a ball in the cart nearly in tears because it was hurting him. I took him to the bathroom thinking maybe it was because he was holding his pee. He had very little urine to even pee out and still he said it was hurting. I asked him if it hurts to pee and he had told me no. I don't have the authority to take him to the doctor. But does anyone have any ideas why his penis or testis (not exactly sure which one) could be in so much pain? I feel so bad for him. I give him Tylenol and an ice pack when it hurts its worst and it seems to help some of the time.

Also, I'd like to add, it is not from him "playing with" or messing with his privates, he never really messes with it and if he had it's not enough for anyone to notice.

Thanks guys.

Edit:

I also forgot to add.

He had a botched circumcision at birth and when he was 2 and a half he had a corrective surgery, but they couldn't get the entire foreskin off.