In France, colorectal cancer (CRC) is the second leading cause of cancer death. Its organized screening (Organized ColoRectal Cancer Screening: DOCCR), now carried out by immunological test for occult blood in the stool, has proven its effectiveness. When the immunological test is positive, the Haute Autorité de Santé recommends a total colonoscopy. In 5 to 10% of cases, this colonoscopy is incomplete. The renewal of the endoscopic procedure or the performance of additional second-line examinations are then recommended. At present, however, the respective place of second-line examinations to be performed in this situation is not the subject of specific and validated recommendations.

Inclusion criteria:

• Age between 50 and 75 years old at the time of the colonoscopy
• With incomplete colonoscopy performed in 2018 after a positive fecal immunological test as part of the DOCCR
• Patient whose follow-up has ended
• Patient living in the Grand-Est region and in the department of the site concerned
• Examination carried out by a gastroenterologist from the Grand-Est region
• Subject not having expressed, after information, his opposition to the reuse of his data for the purposes of this research

Exclusion criteria:

• Age ≥ 76 years at the time of colonoscopy
• Colonoscopy performed after a positive Hemoccult® test (screening technique older than the immunological test and different sensitivity / specificity)
• Colonoscopy performed before the fecal immunological test
• Gastroenterologist performing the examination practicing outside the Grand-Est region
• Subject not able to understand the objectives of this research
• Subject under judicial control
• Subject under tutorship or curatorship

Subject aged between 50 and 75 years old at the time of the colonoscopy with incomplete colonoscopy performed in 2018 after a positive fecal immunological test as part of the DOCCR