The general definition of constipation is having fewer than three bowel movements a week and stools are difficult to pass. When constipation becomes a chronic condition, the infrequent bowel movements or difficulty to pass stools persists for several weeks or longer. Although constipation is a common complaint, it may interfere with the ability to go about daily tasks. Chronic constipation may also cause people to strain excessively to have a bowel movement. Constipation most commonly occurs when the stool moves too slowly through the digestive tract or cannot be eliminated from the rectum, causing the stool to become hard and dry.