The primary objective of this study is to prospectively determine and precisely estimate the incidence of Internal Anal Sphincter (IAS) Injury at 12 months following colectomy with Transrectal NOSE.

Inclusion Criteria:

1. Male or female, aged above 18 years, inclusive.
2. Patients scheduled for an elective laparoscopic or robotic-assisted colectomy above sigmoid colon.
3. Deemed a suitable candidate for the Transrectal NOSE procedure by the treating surgical team, based on tumor size (generally, largest diameter < 4 cm), tumor T stage(1-3), location, and patient anatomy.
4. American Society of Anesthesiologists (ASA) physical status classification of I, II, or III.
5. Able to understand the purpose, procedures, potential risks, and benefits of the study and willing to provide written informed consent, as approved by the Institutional Review Board (IRB).
6. Willing and able to comply with all scheduled follow-up visits and assessment procedures outlined in the protocol.

Exclusion Criteria:

1. Pre-existing moderate-to-severe fecal incontinence, defined as a Wexner incontinence score > 8.
2. History of any prior anal surgery (e.g., sphincteroplasty, artificial sphincter implantation, fistulotomy), major pelvic surgery (e.g., hysterectomy, radical prostatectomy), or pelvic radiation therapy.
3. Confirmed diagnosis of Inflammatory Bowel Disease (Crohn's disease or ulcerative colitis).
4. The planned surgical procedure requires a protective stoma.
5. Uncorrectable coagulopathy identified on preoperative assessment.
6. Known neurological condition affecting bowel control (e.g., spinal cord injury, multiple sclerosis, significant post-stroke deficits).
7. Cognitive impairment, severe psychiatric illness, or other condition that would interfere with reliable completion of questionnaires or compliance with the protocol.
8. Currently pregnant, breastfeeding, or planning to become pregnant during the study period.
9. Concurrent participation in another interventional clinical trial that could potentially interfere with the study outcomes.
10. Any other condition which, in the professional opinion of the investigator, makes the subject unsuitable for participation in this study.

Individual participant data (IPD) will not be shared due to strict restrictions imposed by our Institutional Review Board (IRB) and local data privacy regulations. These policies prohibit the external dissemination or public sharing of patient-level data to ensure the utmost protection of patient confidentiality and privacy. Only aggregated data will be shared through scientific publications.