This clinical trial assesses the safety and effectiveness of a new device called the Flex Robotic System in the surgical removal (resection) of colorectal lesions. When an area of abnormal tissue called a lesion is found in the colon or rectum, it is often not known if the lesion is cancerous or non-cancerous. Recommendation to remove the lesion may be made. Current methods of resection can be challenging and time-consuming. The Flex Robotic System is a new device that provides a stable working environment, better ability to grasp and cut lesions, and better tissue handling when performing a resection. The Flex Robotic system may be more effective at removing colorectal lesions than standard resection techniques.

PRIMARY OBJECTIVE:

I. To assess the rates of complete en bloc resection and adverse events of the Flex Robotic System for distal colorectal lesions.

OUTLINE:

Patients undergo resection with Flex Robotic System on study. Patients also undergo colonoscopy with or without rectal endoscopic ultrasound at screening.

Inclusion Criteria:

• Age >= 22 years (minimum age approved for use)
• Polypoid (0-Is) and non-polypoid (0-IIa, 0-IIb and 0-IIc) lateral spreading lesions according to Paris classification
• Colorectal lesions situated between 5 and 15 cm from the dentate line
• Colorectal mucosal lesions ranging from 1.5 to 7 cm in maximum diameter
• Colorectal subepithelial lesions < 2 cm in size
• Absence of uncorrectable bleeding disorder or coagulopathy
• Platelet count > 50,000
• International normalized ratio (INR) < 1.5
• Ability to give informed consent

Exclusion Criteria:

• Inability to receive general anesthesia
• Presence of medical conditions for which a transanal approach is contraindicated (e.g., anal stricture, radiation proctopathy)
• Excavated (0-III) colorectal lesions according to Paris classification
• Suboptimal colon preparation
• Clinical discretion of the provider