Constipation is a very common problem in chidlren and one that is often left untreated by a child's doctor. If a pediatrician or family doctor doesn't sit down and talk with the child and his parent or parents and always take a diet history, the problem can go untreated for a long time.
In the June 11, 2013 New York Times, there was an article about constipation by Dr. Perri Klass. She commented about the connection of too early potty training by strict parents, poor diet, and the problem about using dirty school bathrooms. These are all important points, but an important problem not discussed was that constipation can be the presenting problem in celiac disease. Most doctors connect diarrhea or loose bowel movements with celiac disease. However, a good friend who is a pediatrician and has celiac disease told me of this connection many years ago.
Abdominal pain can be a presenting sympton of constipation and one that is commonly seen in the ER. I remember seeing a doctor's child on a Saturday afternoon in my office, who was complaining of abdominal pain. His parents were afraid he had an appendicitis. In feeling his abdomen and asking when he had his last bowel movement, I suspected the child was constipated. A rectal examination confirmed this and also there was not the abdominal pain you find with an appendicitis. The parents took him home and after a pediatric Fleet enema, the little boy was fine. He was a big milk drinker and ate apples and banannas, as his only fruits. These can all be constipationg. Also, if a child has large hard stools, a painful rectal fissure can which may keep a child from even trying to go to the bathroom.