Showing papers by "Peter A. Bampton published in 2002"

The Proximal Colonic Motor Response to Rectal Mechanical and Chemical Stimulation

Abstract: We aimed to determine whether rectal distension and/or infusion of bile acids stimulates propagating or nonpropagating activity in the unprepared proximal colon in 10 healthy volunteers using a nasocolonic manometric catheter (16 recording sites at 7.5-cm spacing). Sensory thresholds and proximal colonic motor responses were assessed following rectal distension by balloon inflation and rectal instillation of chenodeoxycholic acid. Maximum tolerated balloon volume and the volume that stimulated a desire to defecate were both significantly (P < 0.01) reduced after rectal chenodeoxycholic acid. The frequency of colonic propagating pressure wave sequences decreased significantly in response to initial balloon inflations (P < 0.05), but the frequency doubled after subsequent chenodeoxycholic acid infusion (P < 0.002). Nonpropagating activity decreased after balloon inflation, was not influenced by acid infusion, and demonstrated a further decrease in response to repeat balloon inflation. We concluded that rectal chenodeoxycholic acid in physiological concentrations is a potent stimulus for propagating pressure waves arising in the proximal colon and reduces rectal sensory thresholds. Rectal distension inhibits all colonic motor activity.

Applying evidence-based guidelines improves use of colonoscopy resources in patients with a moderate risk of colorectal neoplasia.

Abstract: Objectives: To determine whether applying National Health and Medical Research Council (NHMRC) guidelines for colorectal cancer prevention would reduce the number of follow-up colonoscopies. Design: A prospective audit of colonoscopic surveillance decisions before and after the intervention. Setting: The endoscopy suite at a metropolitan tertiary hospital three months before and after January 2000. Intervention: Dissemination of NHMRC guidelines, and supervision of application of the guidelines by a nurse coordinator. Subjects: We compared colonoscopic surveillance decisions before and after the intervention in two groups of 100 consecutive patients after polypectomy and in two groups of 50 consecutive patients with a family history of colorectal cancer after a normal colonoscopy. Main outcome measures: Change in concordance of decisions with NHMRC guidelines; and effect on number of follow-up colonoscopies. Results: After the intervention, the proportion of postpolypectomy surveillance decisions matching the guidelines increased from 37% to 96% (P < 0.05). The mean time to repeat colonoscopy after polypectomy increased from 2.7 to 3.5 years (P < 0.005) (ie, a 23% reduction in the number of postpolypectomy surveillance colonoscopies performed per year). Likewise, the proportion of family-history surveillance decisions matching the guidelines increased from 63% to 96%. Adhering to the guidelines resulted in a 17% reduction in colonoscopies performed on the basis of a family history of colorectal cancer. Conclusions: Supervised application of evidence-based guidelines to a colorectal cancer surveillance program significantly reduces the number of surveillance