Pressure response of human colon to intraluminal distension.

Pressure response to intraluminal distension was recorded in the ascending and descending colon of six subjects awaiting closure of transverse colostomies to assess and compare compliance in different regions of the human colon. Resistance to distension was significantly greater in the descending colon at intraluminal volumes of 30 ml or greater (P less than 0.01). An equal number of postmortem studies, representing passive connective tissue resistance, demonstrated a similar but more pronounced difference (P less than 0.001), which was maintained after correction for initial intraluminal diameter differences (P less than 0.001). The differences between in vivo and postmortem results indicated an active muscular component in the response of the ascending colon to distension compared with a totally passive distal response. These results support the concept of a functional division in the human colon.