Severe constipatation in my 4 yr old- very picky eater?

Doctor can evaluate: If a 4 year-old is pushing when pooping, or pooping firm poops, a parent can try giving the child 8 ounces of prune juice each day. If the child doesn't like prune juice, one can try giving half prune / half apple juice. Usually, laxatives are needed. There are flavored, over-the-counter laxatives that kids like. The doctor can evaluate and offer ideas, to truly get rid of persistent constipation.