RATIONALE: Rectal reconstruction after surgery to treat rectal cancer may help patients keep some of their bowel function. It is not yet known which method of rectal reconstruction is most effective after surgery.

PURPOSE: This randomized phase III trial is studying three different methods of rectal reconstruction to compare how well they work in treating patients who are undergoing surgery for rectal cancer.

This is a randomized, multicenter study. Patients are stratified according to participating center, gender, distance of the distal tumor margin from the dentate line (> 5 cm vs ≤ 5 cm), age (< 70 vs ≥ 70), neoadjuvant chemoradiotherapy (yes vs no), and distant metastasis (M0 vs M1). Patients are randomized to 1 of 3 treatment arms.

• Histologically proven rectal adenocarcinoma or rectal adenoma with/without neoadjuvant radiochemotherapy
• Total mesorectal excision needed
• Age ≥ 18 years
• Clinically normal function of the sphincter muscles (no history of frequent fecal incontinence for liquid or solid stools)
• Any T, any N, any M or adenoma
• An R0-resection is expected (liver metastases planned to be simultaneously
• Written informed consent, signed and dated by the patient and the investigator
• Completed baseline quality of life questionnaire

Exclusion criteria:

• Rectal tumor other than adenocarcinoma or adenoma
• Previous rectal cancer surgery, other than local excision within the last 2 months
• Histologically proven chronic inflammatory bowel disease
• Contraindications to any of the 3 surgical techniques
• BMI > 35
• Patients with psychiatric, addictive or any disorder that would prohibit the understanding and giving of informed consent, completing the QL questionnaires and/or following the structured interview
• Inability to read and understand any of the languages available on the QL questionnaires,and spoken during the interview (German, French, Italian)