Patients whom meet all eligibility criteria will be assigned random 1:1 to one of the following arms:

• ECPS group: Echelon Circular™ Powered Stapler (n=270)
• MCS Group: manual circular staplers (n=270) Patients will be followed during 30 days in order to evaluate the primary endpoint.

Anastomotic Leakage (AL) is the complication that most concerns colorectal surgeons. It leads to prolonged postoperative stay, increased costs, risk of reoperations and a permanent colostomy, together with an increase in morbidity and mortality.

The novel Echelon Circular™ Powered Stapler (ECPS) (Ethicon, Somerville, NJ, USA), introduces design changes that could decrease the rate of technical errors and improve clinical outcomes. The powered stapler decreases the force needed on firing the device, improving stability at the anastomotic site. Atraumatic Gripping Surface Technology reduces the compressive forces on tissues, and along with 3D Stapling Technology allows a better compression distribution throughout the anastomosis and a better hemostasis.

This is a multicenter, randomized, open-label, controlled with parallel groups clinical trial, with 8 participant sites in total (4 sites in Spain and 4 sites in France), to include an approximate sample size (n) of 570 patients who will undergo a colorectal anastomosis after Hartmann reversal, left colectomy, sigmoidectomy or anterior rectal resection, for benign or malignant pathology.

540 patients assigned randomly 1:1 to assess whether technical improvements of Echelon Circular™ Powered Stapler (ECPS) have an impact on left-sided colorectal Anastomotic Leakage (AL) rate compared to current manual circular staplers (MCS).

Anastomosis could be performed open, laparoscopically or with robotic assistance.

After surgery, patients will be followed during 30 days in order to evaluate the primary endpoint.

Inclusion Criteria:

• Patient or its legal representative informed consent.
• Age ≥ 18 years.
• Patients who will undergo a colorectal anastomosis after left colectomy, sigmoidectomy or anterior rectal resection, for benign or malignant pathology (NOTE: Hartmann reversal cases also included).

Exclusion Criteria:

• Diverting stoma.
• Emergency surgery.
• American Society of Anaesthesiologists (ASA) score ≥ IV.
• Transanal total mesorectal excision approach.