Hi my son was born with Gastroschisis. We were very lucky and thankful nothing was dead and all went back in normally and with excellent progress. However his whole life his has had large bowel movements that would put grown men to shame. They are not rock solid. He has them on a daily basis. There has been a few times that it was bigger than he could handle and took him a minute with a rough little road. Should I be more concerned?
Kids with gastroschisis generally will do fine and have no bowel problems at all. I suspect the constipation is just coincidental.
I don't know how old he is. Regardless, I would try some consistent, daily stool softening measures for at least a couple months. This could simply be some plum juice, added fiber bars, or if you want, some Miralax, a safe and extremely effective OTC softener, that is generally the got to med we use. Just be sure it is daily. My dose for a kid with adult size stools, regardless of age, is about one cap (the top of the jug is a measuring cap) daily, mixed in a 4-6 oz serving of a liquid of choice.
If you don't do this, the possibility of developing encopresis, a persistent leakage of stool, is a good chance.
Good luck, Dr. Olson