More bulk may help, juices, try the probiotics they have now they are very good and taste great and they work , they do yoghort, pudding and even drinks with probiotics ...Beans work well , cereals of course ,make sure he eats a breakfast there are cereal bars now for picky kids .
i didn't think of probiotics...thanks!!
Try them they are very good and they have yoghort and puddings now really good flavors even cheesecake ... ..
Have you looked into adding something like oat bran or psyllium husk in his diet? You can usually find these at a health food store and all it takes is a little bit. If you hide it in pudding or yogurt it might go unnoticed. Just be a little careful with dairy cause it can make people really constipated.
Also make sure to try to get him to drink more fluids- water is really important to help push things along, but if he won't drink it maybe apple or orange juice?
Also maybe talk to his ped to see what to watch out for as far as hemorrhoids go. If he's straining it's possible he has hemorrhoids and it hurts to poo.