Keep things moving 1
All kinds of things may cause constipation in children. It could be potty-training stress, lack of fluids or poor bowel habits among others. If, however, a child has not had at least one bowel movement every other day, or if movements are painful and more than normal pushing is needed or there is blood in the stool, it may be worth going to see a paediatrician.
1. http://www.webmd.com/children/features/digestive-doctor. Accessed December 2014.