Contractile Frequency Patterns of the Human Colon

Unlike myoelectrical frequency patterns, the regular contractile activity of the human colon in vivo is poorly understood, especially with regard to the proximal portions of the viscus. For this reason, we looked for contractile patterns (defined as a regular sequence of waves occurring consecutively for at least 2 minutes, at various frequencies) in prolonged (24-hour) manometric recordings obtained in 20 healthy volunteers of both sexes. Manometric investigations were done by means of a colonoscopically positioned multilumen poly-vinylcloride (PVC) probe and low-compliance infusion system. Systematic analysis of the tracings showed that regular contractile activity is scarce in the human colon, in that it accounts for only about 6% of total contractile activity; contractile patterns vary in frequency from two to eight cycles per minute, with three cycles per minute (which represents 80% of regular activity) predominating; regular contractile activity is chiefly encountered in the distal (descending and sigmoid) colon, where it represents about 50% of motility; and unlike the human upper gut and anorectal area, and the dog colon, the regular activity of the human colon is not organized in a cyclic fashion.