Constipation is a decrease in the frequency of stool (the body's waste product) or difficulty in the formation or passage of stool.

Constipation is determined in the colon (large intestine), which is responsible for packaging and eliminating stool.

As food moves through the colon, it absorbs water while forming stool. Muscle contractions (squeezing motions) in the colon push the stool toward the rectum (the lower 8 to 10 inches of the large intestine). By the time stool reaches the rectum, it is...