Outpatient colonoscopy is a safe procedure with a low risk of acute complications. Improving bowel preparation enhances completeness. Sedation/analgesia is conducive to both completeness and the lowering of the risk of acute complications.

The risk of invasive carcinoma in colorectal adenomas can only be adequately described by a complex model of the interactive effects of patient and adenoma characteristics on the main factors of size and site.

A multivariate analysis of 11,380 adenomas detected at the first total colonoscopy showed that the factors size and site, both of which can be assessed by endoscopic inspection alone, were found to enable a statistically and clinically adequate assessment of the malignancy risk.

Background: Patients who have had a colorectal adenoma are likely to develop a metachronous adenoma and therefore need to be kept under surveillance. It is essential to avoid unnecessary examinations by tailoring the frequency of follow up examinations to individual risk. Methods: A total of 3134 patients undergoing endoscopic removal of colorectal adenomas were prospectively recorded on the Erlangen Registry of Colorectal Polyps between 1978 and 1996. A multivariate analysis of 1159 patients on long term follow up was performed to identify risk factors determining surveillance intervals for patients with metachronous adenomas of advanced pathologythat is, adenomas >10 mm or with high grade dysplasia or invasive carcinoma. Results: Univariate analysis revealed that sex, parental history of colorectal carcinoma, and characteristics of the initial findings-that is, size, multiplicity, and amount of villous structure-were significant predictors of metachronous adenomas of advanced pathology. On the basis of multivariate analysis, two risk groups were identified: (1) patients with no parental history of colorectal carcinoma with only small (<10 mm) tubular adenomas at the initial clearing examination have a very low risk, and we estimated that 10% will develop advanced metachronous adenomas after 10 years; (2) the high risk group contained all other patients, 10% of whom will show metachronous adenomas of advanced pathology at follow up after only three years. Conclusions: The risk of developing metachronous adenomas with advanced pathology can be stratified for various patient and adenoma characteristics. Surveillance intervals can be scheduled for low risk (10 years) and high risk (three years) patients. Risk related follow up thus helps to avoid unnecessary examinations.

Background-Anthranoid laxatives are the most commonly used purgatives in the therapy of acute and chronic constipation. Recent experimental data and a prospective cohort study provide evidence of a possible risk of anthranoid use for the development of colorectal neoplasms. Materials and methods-We performed a prospective case control study at the University of Erlangen to investigate the risk of anthranoid laxative use for the development of colorectal adenomas or carcinomas. A total of 202 patients with newly diagnosed colorectal carcinomas, 114 patients with adenomatous polyps, and 238 patients (controls) with no colorectal neoplasms who had been referred for total colonoscopy were studied. The use of anthranoid preparations was assessed by standardised interview, and endoscopically visible or microscopic melanosis coli was studied by histopathological examination. Results-There was no statistically significant risk of anthranoid use for the development of colorectal adenomas (unadjusted odds ratio 1.0; 95% CI 0.5-1.9) or carcinomas (unadjusted odds ratio 1.0; 95% CI 0.6-1.8). Even after adjustment for the risk factors age, sex, and blood in the stools by logistic regression analysis the odds ratio for adenomas was 0.84 (95% CI 0.4-1.7) and for carcinomas 0.93 (95% CI 0.5-1.7). Also, there were no diVerences between the patient and control groups for duration of intake. Macroscopic and high grade microscopic melanosis coli were not significant risk factors for the development of adenomas or carcinomas. Conclusion-Neither anthranoid laxative use, even in the long term, nor macroscopic or marked microscopic melanosis coli were associated with any significant risk for the development of colorectal adenoma or carcinoma. (Gut 2000;46:651-655)