My 4 year old son (5 in march) has started complaining that his penis is hurting and it seems to coincide with having an erection. He has had them before but they have been a normal frequency and has never complained of pain before. It happens several time a day now. There are no signs of anything else being sore in that area. He has also been complaining of tummy ache most mornings but thought this was just post Christmas blues and not wanting to go back to school - could they be linked or am I reading too much into it?