Constipation is a relative term. Normal patterns of bowel elimination vary widely from person to person and you may not have a bowel movement every day. While some healthy people may have consistently soft or near-runny stools, others may have consistently firm stools, but no difficulty in passing them.

When the stool is hard, infrequent, and requires significant effort to pass, you have constipation. The passage of large, wide stools may tear the mucosal membrane of the anus, especially in children. This can cause bleeding and the possibility of an anal fissure.

Constipation is most often caused by a low-fiber diet, lack of physical activity, inadequate intake of fluid each day, or delay in going to the bathroom when you have the urge to defecate. Stress and travel can also contribute to constipation or other changes in bowel habits.

Other times, diseases of the bowel (such as irritable bowel syndrome), pregnancy, certain medical conditions (like an underactive thyroid or cystic fibrosis), mental health problems, neurological diseases, or medications may be the reason for your constipation. More serious causes, like colon cancer, are much less common.

Constipation in children often occurs if they hold back bowel movements when they aren't ready for toilet training or are afraid of it.