my 3 and a half year old son who was toilet trained six months ago has started to constantly leak into his pants.He just can't seem to hold on to the smallest amount of urine and I have to change him up to six/seven times a day.I know that chidren sometimes have accidents when they are concentrating on something but my son has constant leaking rather than one accident.Is this normal? Is he just being lazy? Or is it something more serious like a bladder infection?He seems to be getting worse.Any advice please?