Neither of my two CAH kids have had problems with that. If he has frequent loose bowel movements, make sure he gets plenty of fluids to replace what he looses. Since I have four kids it’s easy for me to tell what symptoms are CAH related and what are not. As long as my kids’ diet is healthy (a minimum of processed sugar and flour. Lots of whole grains, vegetables and fruit. A good supply of protein daily) their gastro-intestinal problems are minimal.