DS, 6.3 is only opening his bowles twice a week and he's straining really badly. I mean to the point of breathlessness. Sorry if TMI but he is passing 2/3 'logs' about 5-8" long each time he goes. 
He has at least 5 portions of fruit and veg a day and drinks plenty, probably more than most children his age. He swims twice a week so gets lots of excercise.
He has had allergy problems, hayfever and an unknown.
I am thinking this isn't normal?
Any advice/ ideas?