the best way to treat constipation
in any child is by dietary modification rather than medicines, that will only give temporary solution.
some things you can do to modify his diet are
1. repalce white bread with whole grain bread like brown bread or multigrain bread.
2. avoid giving readily processed food available in market.
3. give raw fruits as they are rich in fibres and fruit juice is a very good laxative. but avoid banana as this tends to hold up the intestine. apple, oranges, prunes ets age goood for constipation even in small children.
if he is not able to take it raw, you can boil them or give jellies made out of them
or you can give pure fruit juices without added sugar
4 avoid giving carbonated beverages to the child
5. try to make him move and do phusical activities as much as he can. like a walk with you whenever you are free, this helps moving bowel
6. give him plenty of water to drink as it is a very good softner and will help bowel move
7. in some acute cases when its is very discomforting to your child you can give him glycerine suppository through anal opening to relieve constipation. though its only a temporary method and can not be employed every now and then.
since you have tried many medicines for your son, try to do the things i suggested and can post to me for further suggestions
thanks for your query