Constipation occurs when stool or waste material moves too slowly through the large intestine. Feces that stay in the bowel too long before elimination become hard and dry. This results in difficult, painful, and infrequent bowel movements. In many cases, constipation is harmless, but it can significantly lower your quality of life. It's not a disease, but it might be a symptom of a disease.
Many people believe they are constipated when they're not, thinking that less than one bowel movement a day is abnormal. In fact, as little as twice a week is fine so long as you go easily when you feel the need. A normal bowel movement, no matter how often, should be soft yet hold its shape and be easy to pass without needing to strain.