Transit of solids through the human colon: regional quantification in the unprepared bowel

Abstract

We used a noninvasive method to label the solid phase of contents in the unprepared human colon. 111In-labeled Amberlite pellets (0.5-1.8 mm diam) were placed in a gelatin capsule that was then coated with a pH-sensitive polymer (methacrylate). In vitro, the capsules disintegrated in simulated small bowel contents within 1-2 h; when ingested by healthy subjects, capsules released radiolabel in the distal ileum or proximal colon in 13 of 15 subjects. Transit of 111In-pellets through the unprepared colon could then be quantitated radioscintigraphically. Segmental transit was defined in the ascending (AC), transverse (TC), descending (DC), and rectosigmoid (RS) colon. Radioactivity was also quantitated in stools. At 12 h, radioactivity was most obvious in the AC (59 +/- 11%, mean +/- SE) and the TC (21 +/- 6%); at 24 h, counts were distributed equally between AC, TC, and stools (P greater than 0.05); by 48 h, 56 +/- 11% counts had been excreted, although 30 +/- 10% remained in the TC. At 24 and 48 h, the amount in DC or RS was lower (P less than 0.05) than in the TC or in stools. Emptying of the AC was characterized by an initial lag period, when no counts emptied into the TC, followed by a period of emptying that was approximately linear. Thus this simple approach is able to label contents in the healthy human colon. The ascending and transverse colon appear to be sites of storage of solid residue, whereas the left colon and rectosigmoid function mainly as conduits.

Restraint stress stimulates colonic motility via central corticotropin-releasing factor and peripheral 5-HT3 receptors in conscious rats

“…As a conduit, the distal colon mainly serves to expel the fecal bolus, displaying a pattern of intense peristaltic contractions and mass action associated with the propulsion of dehydrated feces. In contrast, the proximal colon serves as a reservoir and is considered to be the primary site of storage for feces to absorb water (25,33). It is conceivable that colonic function may be altered selectively by diseases and that overall assessments of whole colon transit could overlook important regional abnormalities.…”

Outcome of Sigmoid Compared to Ileal Orthotopic Bladder Substitution in Terms of Micturition and Defecation Parameters in an 8-Year Long-Term Follow-Up

“…Because of its anatomic position within the pelvis, the ureteral anastomosis is relatively simple and the sigmoid pouch can easily be brought to the membranous urethra [1] . In addition, the loss of a sigmoid segment has only minimal effects on nutrition and defecation of the patient [13] . The subjective success of an orthotopic bladder replacement is largely dependent on the achieved continence status of the patient.…”

Gastrointestinal Motility, Part 2: Small-Bowel and Colon Transit

“…The rate of transit of solid particles depends on their size, and intracolonic visualization and localization can be difficult given the limited anatomic landmarks. Radiopaque markers, however, have been shown to correlate well with scintigraphic measurement of colon transit (25,26). The wireless motility capsule is also used to measure colon transit.…”