When a constipated child passes a large, hard, dry stool, the bowel movement can cause pain. This pain may be caused by:

• Pushing with the abdominal muscles to move the stool out of the rectum.
• Stretching of the opening of the digestive tract (anus).
• A tear in the anal opening (anal fissure).

Pain caused by passing a hard, dry stool can trigger a vicious cycle: Pain discourages a child from trying to have a bowel movement, which worsens the constipation, which causes more pain. This cycle may lead to persistent (chronic) constipation.