Sigmoid Colectomy — Procedure Guide, Recovery & Risks | MyMedicPlus

Sigmoid colectomy is a surgical procedure to remove the sigmoid colon — the S-shaped final segment of the large intestine located between the descending colon and the rectum in the left lower abdomen. The operation involves resecting the diseased sigmoid segment, mobilising the descending colon, and anastomosing (joining) it to the rectum to restore bowel continuity.

The procedure is most commonly performed laparoscopically (keyhole), with 4–5 small ports (5–12 mm), though robotic-assisted and hand-assisted techniques are also used. Open surgery through a laparotomy is reserved for emergency presentations (perforation, obstruction, haemorrhage) or cases with extensive adhesions or oncologically complex anatomy. Laparoscopic sigmoid colectomy offers shorter hospital stay, less post-operative pain, faster recovery, and lower wound complication rates than open surgery — now the preferred approach at most centres.

The sigmoid colon, approximately 40 cm in length, is a common site for diverticular disease (pouches in the bowel wall) and colorectal cancer, making sigmoid colectomy one of the most frequently performed colorectal procedures. At specialist colorectal surgical centres, surgeons perform laparoscopic sigmoid colectomy for both benign and malignant disease with excellent safety profiles.

The most common indication for sigmoid colectomy is recurrent or complicated diverticulitis. Diverticulitis — inflammation/infection of diverticulae (outpouchings) in the sigmoid colon — is electively operated after two or more episodes of uncomplicated diverticulitis that each required hospital admission and IV antibiotics, particularly in younger patients (under 50) at higher risk of further attacks. Emergency surgery is required for complicated diverticulitis: perforation with peritonitis (Hartmann's procedure — end colostomy), abscess not amenable to percutaneous drainage, fistula formation (colovesical, colovaginal), or bowel obstruction from stricture.

Sigmoid colon cancer is the second most common indication. Oncological sigmoid colectomy requires a formal cancer resection with high ligation of the inferior mesenteric artery, wide mesenteric resection, and harvesting of a minimum of 12 lymph nodes for staging. Total mesorectal excision (TME) technique principles are applied at the rectosigmoid junction. Laparoscopic colectomy for colon cancer has equivalent oncological outcomes to open surgery, proven by the COLOR, CLASICC, and COST trials.

Other indications include sigmoid volvulus (bowel twisting causing obstruction) not manageable by endoscopic decompression, and large benign sigmoid polyps not removable by endoscopic polypectomy.

Preoperative preparation includes bowel preparation in selected cases (mechanical bowel prep with oral antibiotics), antibiotic prophylaxis (cephalosporin plus metronidazole), and DVT prophylaxis (low molecular weight heparin and TED stockings). Enhanced recovery after surgery (ERAS) protocols are standard, including pre-operative carbohydrate loading, early mobilisation, multimodal analgesia, and avoidance of routine nasogastric tubes and drains.

Laparoscopic technique: general anaesthesia with epidural or thoracic paravertebral block for post-operative analgesia. The patient is in a modified Lloyd-Davies position (lithotomy and Trendelenburg). CO2 pneumoperitoneum at 12–15 mmHg; 4–5 trocars placed. A lateral-to-medial dissection approach mobilises the sigmoid colon by incising the left paracolic gutter, then identifying and protecting the left ureter (runs directly beneath the peritoneum over the iliac vessels), gonadal vessels, and autonomic nerve plexuses.

The sigmoid mesocolon is divided with a vessel-sealing device (Ligasure, Harmonic). The inferior mesenteric artery (IMA) is divided at the aorta for cancer (high tie) or preserving the left colic branch for benign disease. The sigmoid colon is divided proximally at the descending/sigmoid junction and distally at the rectosigmoid. The specimen is extracted through a 4–6 cm Pfannenstiel (lower abdominal) incision or extended port site, and a circular end-to-end stapled anastomosis (EEA stapler, 29–33 mm) is constructed by passing the stapler transanally and firing through the rectal stump. A leak test (air insufflation into the rectum with the anastomosis submerged in saline) confirms anastomotic integrity. Total operative time: 2–3 hours.

Enhanced recovery after surgery (ERAS) protocols allow clear fluids on the day of surgery and a light diet by day 1–2. Routine nasogastric tubes and abdominal drains are not used in elective cases without specific indications. Patients are mobilised to sit and walk on day 1, and continue progressive mobilisation each day. Hospital stay is typically 3–5 days for laparoscopic elective surgery, compared to 7–10 days for open surgery.

Post-operative analgesia uses a multimodal approach: regular paracetamol and NSAIDs, patient-controlled opioid analgesia for breakthrough pain, and epidural or paravertebral regional anaesthesia. Bowel function returns in 2–4 days (passing wind and then stool). Patients are discharged when tolerating oral diet, mobilising independently, and with pain controlled on oral medications.

At home, a normal diet is resumed, though high-fibre foods may be gradually reintroduced over 4–6 weeks. Heavy lifting (greater than 5 kg) and strenuous exercise are avoided for 4–6 weeks. Return to driving at 4–6 weeks; return to office work at 3–4 weeks. Wound clips are removed at 7–10 days. Oncological patients begin adjuvant chemotherapy (FOLFOX) at 4–6 weeks if indicated by pathology.

Anastomotic leak — breakdown of the bowel join — is the most feared complication, occurring in 3–5%. It presents as fever, abdominal pain, and raised inflammatory markers at 3–7 days post-operatively. Minor leaks may be managed conservatively with antibiotics and radiological drainage; major leaks require urgent return to theatre, washout, and often formation of a temporary defunctioning stoma (usually a loop ileostomy) to protect the anastomosis during healing.

Wound infection occurs in approximately 5% of laparoscopic cases and 10–15% of open cases. Ileus (prolonged failure of bowel motility) occurs in 10–15%, requiring nasogastric decompression and NPO management. Left ureteric injury, though rare (less than 1%), is a serious complication requiring urological repair; careful intraoperative ureteric identification prevents this.

Haemorrhage requiring transfusion occurs in 2–3%. Deep vein thrombosis and pulmonary embolism occur in 1–3% despite pharmacological prophylaxis. Sexual dysfunction (retrograde ejaculation in men, dyspareunia in women) from autonomic nerve injury occurs in approximately 5–10% of cases involving the rectosigmoid, particularly with low dissection. Conversion to open surgery in laparoscopic colectomy occurs in 5–10% of cases.

Laparoscopic sigmoid colectomy reduces hospital stay by 2–3 days and returns patients to work and normal activities 1–2 weeks earlier than equivalent open surgery. Post-operative pain scores are significantly lower, analgesic requirements reduced, and wound complication rates decreased by 50–60%.

For diverticular disease, sigmoid colectomy provides definitive treatment eliminating the diseased segment, preventing further diverticulitis attacks in over 95% of patients. Quality of life, including freedom from recurrent hospital admissions, antibiotic courses, and the anxiety of recurrent disease, is substantially improved.

For colorectal cancer, laparoscopic sigmoid colectomy achieves equivalent oncological outcomes to open surgery — the COST, CLASICC, and COLOR randomised trials all confirmed equivalent 3-year survival, recurrence rates, and lymph node harvest — while providing the short-term recovery advantages of minimally invasive surgery. 5-year survival for stage I sigmoid colon cancer exceeds 90%, stage II 75–85%, and stage III 50–70% with adjuvant chemotherapy, reflecting the importance of early diagnosis.