[Yield of colonoscopy by indication and consequences for colorectal polyp and cancer screening: a prospective survey in Isère, France].

Aim: The aim of this study was to determine yields of colonoscopy by indication, especially after a positive Hemoccult test, in the Isère area in southeastern France where a mass screening campaign for colorectal cancer using the Hemoccult test was conducted in women aged 50 to 69 years.

Method: This prospective survey was conducted with the participation of all gastroenterologists in the Isère department. Information about indications of all colonoscopies performed and their results were collected.

Results: The study involved 1,779 colonoscopies performed for: digestive symptoms (40%), surveillance of colon disease (22%), hematochezia (18%), a family history of colon cancer (10%), anemia, poor general condition or metastasis (4%), and a positive test for blood in the stool (3%). The presence of a pathological colonic condition was significantly related to age (11% of cancers or large polyps after 50 years compared to 3% before), sex (10% of the women with lesions and 15% of the men) and the reason for prescription: after the age 50 a cancer or a large polyp was found in 27% of the cases if the colonoscopy was performed for anemia, metastasis or poor general condition, 21% for hematochezia, 20% for a positive test, 8% for digestive symptoms, and 2% because of a family history.

Conclusion: Positive Hemoccult tests represent only a small part of the indications for colonoscopies performed in the Isère department. However, the screening program should be extended to develop its use given its yield which is equivalent to that of hematochezia and much higher than that of digestive symptoms or family history.