What Causes Constipation?

Symptoms of Functional Constipation

Functional constipation is constipation whose symptoms cannot be linked to any infection or structural abnormality.

At least two of the following during any 12 weeks over the past year:
--- straining during more than one-quarter of bowel movements
--- having lumpy or hard stools during more than one-quarter of bowel movements
--- having a sensation of incomplete evacuation in more than one-­quarter of bowel movements
--- having a sensation that your rectum or anus is blocked during more than one-quarter of bowel movements
--- resorting to manual maneuvers such as using a finger to help facilitate movement during more than one-quarter of bowel movements
--- fewer than three defecations a week.

from here