Review article: colonic sensorimotor physiology in health, and its alteration in constipation and diarrhoeal disorders

Abstract

Aim: To review the physiology of colonic motility and sensation in healthy humans and the pathophysiological changes associated with constipation and diarrhoea. Source: Medline Search from 1965 using the index terms: human, colonic motility, sensation, pharmacology, neurohormonal control, gastrointestinal transit, constipation, diarrhoea and combinations of these. Results: In health, the ascending and transverse regions of colon function as reservoirs to accommodate ileal chyme and the descending colon acts as a conduit; the neuromuscular functions and transmitters control colonic motility and sensation and play pivotal roles in disorders associated with constipation and/or diarrhoea. Disorders of proximal colonic transit contribute to symptoms in idiopathic constipation, diarrhoea‐predominant irritable bowel syndrome and carcinoid diarrhoea. Colonic function in patients presenting with constipation is best assessed clinically by colonic transit time using radiopaque markers ingested orally. Measurements of colonic contractility are less useful clinically but they can help identify motor abnormalities including colonic inertia; in some patients with irritable bowel syndrome, abdominal pain, urgency and diarrhoea are temporally associated with high amplitude contractions, which originate in the proximal colon and traverse the distal conduit at very high propagation velocities. Visceral hypersensitivity contributes to the urgency and tenesmus in irritable bowel syndrome and inflammatory bowel disease. Colonic motility and sensation can be reduced by anticholinergic agents, somatostatin analogues and 5HT3 antagonists. Conclusion: Physiological and pharmacological studies of the human colon have provided new insights into the pathophysiology of colonic disorders, and offer possibilities of novel therapeutic approaches for constipation or diarrhoea associated with colonic motor or sensory dysfunction.

Impact of previous gastric or colonic resection on polyethylene glycol bowel preparation for colonoscopy

“…The altered bowel habit after bowel surgery adapts over a 4-6-month period, gradually returning to a more normal bowel pattern. Second, segmentation into the haustra compartmentalizes the colon, facilitating mixing and clearing in a normal colon [17,18]. In patients who have undergone colonic resection, the loss of the mixing and clearing function of the resected segment may contribute to poor bowel preparation.…”

Effect of 4-(5-Chloro-2-hydroxyphenyl)-3-(2-hydroxyethyl)-6-(trifluoromethyl)-quinolin-2(1H)-one (BMS-223131), a Novel Opener of Large Conductance Ca2+-Activated K+(Maxi-K) Channels on Normal and Stress-Aggravated Colonic Motility and Visceral Nociception

“…Indeed, loperamide whose prolonged use can cause severe constipation was extremely effective in reducing basal as well as stress-induced intestinal motility. On the other hand, a modest and selective reduction in basal colonic motility may be of special help to IBS patients who suffer increased postprandial colonic contractions and a resultant fecal urgency (Camilleri and Ford, 1998).…”

A smooth muscle tone-dependent stretch-activated migrating motor pattern in isolated guinea-pig distal colon

“…chronic constipation and megacolon. In contrast, in carcinoid diarrhoea both muscle tone and propagated contractions are increased (see Camilleri & Ford, 1998). …”

“…In contrast, CMMCs in the murine colon appear to be tone independent, since their propagation and frequency are unaffected by muscle paralysis with nifedipine (Bywater et al 1989;Powel et al 2002). In the human large bowel, both smooth muscle tone and motility increase following feeding, the increase in tone being dependent upon cholinergic nerve activity (see reviews by Camilleri & Ford, 1998;Bassotti et al 1999). Abnormal changes in smooth muscle tone and motility are indicative of gut pathology.…”