This section is from the book "A Manual Of Pathology", by Guthrie McConnell. Also available from Amazon: A Manual Of Pathology.
Constipation, Or Coprostasis, is a condition in which defecation may not be sufficiently frequent, the amount of feces insufficient or abnormally dry and hard. It may be due to deficient motor activity of the colon as a result of weak muscle, deficient reflex activity, inhibition of the motor activity, uncontrolled and irregular motor activity. It may be due also to excessive force required to carry the feces to the pelvic colon. The work to be done by the intestinal musculature is excessive whenever the bulk or the consistence of the feces offers more than a normal degree of resistance, and whenever there is any narrowing of the intestinal lumen.