In colorectal surgery, one of the most feared complications is anastomotic leak (AL). To limit the consequences of AL, it must be diagnosed as early as possible, before it becomes symptomatic. Digestive surgeons use a variety of pre-, per- and post-operative techniques to reduce the rate of anastomotic fistula, but the risk persists, with a rate of 7% reported in the literature. It has been shown that the value of CRP between D1 and D5 correlates with the risk of AL, and that the trajectory between two consecutive days (D1 to D5 post-op) is the most discriminating element in predicting the risk of AF. This assay requires repeated intravenous sampling, which is the opposite of simplifying care. CRP point-of-care testing (POCT) is used in clinical practice, notably in pediatrics and outpatient medicine (in children and adults) to help prescribe probabilistic antibiotic therapy, as the instantaneousness of the result has an impact on patient management. For the diagnosis of AL, CRP POCT assessment could reduce the number of blood samples taken, shorten the time between sampling and medical management in cases of suspected AL, and thus improve the patient's post-operative experience.

Inclusion Criteria:

• Patients undergoing elective (non-emergency) colorectal surgery, regardless of the approach (laparotomy, laparoscopy, robotic) and whether there is a protective ileostomy.

Exclusion Criteria:

• No anastomosis
• Urgent surgery
• Pregnancy or breast-feeding
• Patients under guardianship or trusteeship
• Minor patients