And I found the following:
From: http://www.wholesomebabyfood.com/news/?p=1350There is a difference in the amount of sugars and pectin in apple juice and applesauce; this is why one may help relieve constipation while the other may actually cause it. Apple juice contains more sugars and liquids so it helps relieve constipation. Applesauce is the whole of the fruit. It contains a higher level of pectin – which firms up stools and may thus lead to constipation.Apples contain pectin, which will add bulk to your stools, and their cleansing action will encourage bowel movements. They have a laxative effect yet are also used for to help people get back on a regular diet after suffering bouts of diarrhea.Pectin is what dietitians have been telling us for decades is necessary to keep us regular and to prevent constipation. While pectin will help prevent constipation by helping to keep the bowels regular, it will not help relieve constipation. Be sure not to overfeed your little one applesauce!
Super helpful info to know, and now the poor boy shall have to suffer through a few days of prunes. He seems to like them though (they make me gag), so perhaps it shall not so much be suffering for him.