Inclusion Criteria:  Radiologically proven colonic obstruction of the left colon/upper rectum presumed secondary to a carcinoma Able to give written, informed consent Primary tumor was resectable ECOG score 0 or 1 Haemoglobin greater than 100 g/L after transfusion before chemotherapy, White blood cells greater than 3.0×10# /L Platelets greater than 100×10# / L; Glomerular filtration rate greater than 50 mL per minute as calculated by the Wright or Cockroft formula Bilirubin less than 1.5×Upper Limit of Normal(ULN) ALT and AST less than 2.5×ULN  Exclusion Criteria:  Distal rectal cancers(equal or less than 10cm from the anal verge) Patients with signs of peritonitis and/or bowel perforation Patients who did not give informed consent Patients who were considered unfit for operative treatment or refuse surgery. Patients with suspected or proven metastatic adenocarcinoma; Patients with unresectable colorectal cancer, or planning for palliative treatment.