Acute constipation occurs when a change in bowel habits produces infrequent stools or hard stools that are difficult to pass. Strong laxatives should be avoided in these circumstances. When a change of bowel habit persists for weeks or occurs intermittently with increasing frequency or severity, colonic tumors and other causes of partial obstruction should be suspected. A reduced stool size suggests an obstructive lesion in the distal colon. The common functional causes of chronic constipation hamper normal bowel movements because the storage, transport, and evacuation mechanisms of the colon are deranged.
Psychogenic factors are most common.
Many persons incorrectly believe that daily defecation is necessary and complain of constipation if stool frequency is less than expected. As a result, they abuse the colon with laxatives, suppositories, and enemas. Depression may be associated with failure to defecate daily. A cycle may develop in which depression reduces stool frequency and failure to defecate augments depression. Such people often become chronic cathartic users or spend excessive time on the toilet.