Transit Slowing through the Colon
Propulsive constipation is used to indicate a motor defect characterized by reduced peristaltic contractile activity (diminished thrusting force) or by an increase in contractile segmentation activity (increase in the resistance to aboral movement) (4). These motor alterations of the colon have been verified by means of manometry (reduction and/or absence of peristaltic postprandial activity) (2), or by electromyography (absence of and/or a reduction in lengthy spike activity)(16).
Colic constipation is the term used to indicate the site of the slowing of contents highlighted by radiopaque markers during a radiological examination (5) or with radionuclide markers by means of scintigraphy (3): right-colon constipation, left-colon constipation, and rectal constipation can be characterized by evaluating the segmentary transit times of the large intestine (5).
Severe idiopathic constipation is identified by a noted reduction of bowel frequency, abdominal pain, and a normal-sized colon; it almost exclusively strikes reproductive-aged women (15); it characteristically does not respond to conservative therapy. A diminishing of the large amplitude peristaltic waves can be seen (2) by manometry; in part it corresponds to propulsive constipation characterized by the absence of peristalsis.
Slow transit constipation indicates patients with stasis at the descending or transverse colon without involvement of the ascending colon (7). It is believed that patients with severe idiopathic constipation have slow transit constipation (15).
Colonic inertia is a form of chronic constipation, which for some researchers is characterized by slow transit time in the ascending colon (7), which may be associated with slowing in other segments, while for others it is characterized by reduced peristaltic activity in the colon (2),(16).
Idiopathic megacolon is characterized by the dilation of the colon and stagnation of the feces in the dilated parts without involvement of the rectum.