Terminated by ColubrisMX due to its identification of irregularities in the conduct of the trial (not related to clinical safety or effectiveness of the device)

This study is a prospective, single-arm, multi-center, open-label, staged clinical study.

Overall Objective:

1. To evaluate the safety and effectiveness of the ELS System in subjects undergoing transanal endoluminal procedures in the rectum and distal colon (up to 17 cm from the anal verge).
2. To validate a program for training surgeons and their teams to successfully use the ELS System.

Endoscopic Mucosal Resection (EMR) is the current standard treatment for non-malignant colorectal polyps in the United States. Large colorectal polyps are most often removed piecemeal when using EMR, as en-bloc resection becomes increasingly challenging with increasing lesion size. The major drawback of EMR is its low en-bloc resection rate. The piecemeal nature of the resection hinders margin assessment, which consequently results in low R0 resection rates and causes uncertainty regarding the appropriate treatment plan for the patient going forward. This outcome results in surveillance colonoscopies at shorter intervals to evaluate for recurrence, which in turn, increases patient anxiety and poses a burden on the healthcare system. Endoscopic Submucosal Dissection (ESD) enables en bloc resection and therefore improved histopathological assessment of margins and has been reported to have highly improved R0 resection rates when compared with EMR. ESD is a common treatment option for large colorectal lesions in Asia; however, the technical difficulty and steep learning curve, which are mainly attributed to the lack of traction and countertraction capability, have resulted in low adoption of ESD in the United States.

The ColubrisMX Endoluminal Surgical (ELS) System represents a marked advancement in the removal of non-malignant colorectal lesions. Robotic-assisted instrumentation with bimanual dexterity allows for application of traction and counter-traction and closure of the defect via suturing, and enables the technically challenging, single-handed ESD procedure to be conducted via a two-handed, robotic-assisted, transanal endoluminal surgical approach. The ELS System consists of two main components: the Patient Cart and the Surgeon Console. This system gains access by means of a flexible overtube (Colubriscope) that can be manually inserted up to 17 cm into the distal colon. The ELS System provides full visualization of the surgical site and the ability to manipulate up to two surgical instruments and a robotic-assisted third-party flexible endoscope (Olympus GIF-XP190), which is referred to as the "videoscope". The ELS Surgical Instruments are robotically assisted with full triangulation and articulation with up to 7 degrees of freedom to provide enhanced dexterity in narrow endoluminal anatomy.

Inclusion Criteria:

1. Aged 22-80 years
2. BMI ≤ 40 kg/m2
3. ASA score ≤ 3
4. Subject agrees to participate in the study by giving signed informed consent
5. Benign lesion that is located ≤ 17 cm from the anal verge, such as adenoma, submucosal nodule, or polyp
6. Lesion size is ≤ 7 cm, with size determined according to the American College of Gastroenterology (ACGE) and the American College of Colon and Rectal Surgeons (ACCRS) guidelines as the dimension of the lesion that is greatest in extent.

Exclusion Criteria:

Preoperative:

1. Anatomy unsuitable for endoscopic visualization or endoluminal surgery
2. Prior radiation treatment for colorectal cancer
3. Subject diagnosed with ≥ T1 colorectal cancer
4. Subject with distant metastases
5. Subject requiring Total Mesorectal Excision
6. Untreated active infection
7. Vulnerable population (e.g., prisoners, mentally disabled)
8. Severe concomitant illness that drastically shortens life expectancy or increases risk of therapeutic interventions
9. Breastfeeding or pregnant, or intend to become pregnant during the course of the study
10. Currently enrolled in or discontinued within the last 30 days from a clinical trial of an investigational drug or device, or concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study
11. In the opinion of the Investigator, the subject is unable to comply with the requirements of the study protocol or is unsuitable for the study for any reason.
12. Subjects with immunosuppression drugs (chemotherapy) due to an increased potential for infection and poor healing
13. Subjects with a high cardiac or pulmonary risk (these subjects require clearance from a cardiologist and pulmonologist)
14. Subjects on preoperative blood thinners, i.e., coumadin or heparin, that cannot be weaned prior to surgery
15. History of inflammatory bowel disease

Intraoperative:

1. Existing stricture or anatomical blockage in lower GI tract preventing Colubriscope from reaching desired position.
2. Inadequate bowel prep.
3. Complex anatomical findings not feasible for endoluminal or partial thickness approach.
4. Lesion demonstrates characteristics indicative of cancer, such as failure to lift upon submucosal injection, or any other features that raise the Investigator's suspicion of cancer.
5. Confirmation that lesion is located further than the intended use of the ELS System (past 17 cm from the anal verge).