My almost 5 yr old SWCAH girl also had difficulties with her bowel movements but this started when she was an infant. We keep her on prune juice and the norm fruits & veggies. Aside from her endo, we also have to see a urologist. the urologist has put McKenzie on a strict high fiber diet. We give her a teaspoon and half of Benefiber with her cereal or yogurt in the morning and every Friday after school/daycare we give her a teaspoon of Milk of Magnesia. We have switched to whole grain bread and increased beans, high fiber stuff. We also get 1% milk too. Maybe this will help and not sure if your daughter has a urologist or not but you may wanna look into it.