Colonic Perforation

Colonic perforation is full thickness disruption of the colonic wall with leakage of gas, bacteria and faecal material into the peritoneal cavity or adjacent tissues.

Causes include diverticulitis, colorectal carcinoma, ischaemia, obstruction, inflammatory bowel disease, trauma and iatrogenic colonoscopic injury.

Faecal contamination produces rapidly progressive secondary peritonitis and septic shock.

Free perforation usually causes severe abdominal pain, guarding, rigidity and ileus.

Persistent tachycardia may precede hypotension.

A contained perforation may cause local tenderness, fever and abscess without generalised peritonism.

Advanced contamination produces hypotension, oliguria, altered mentation and metabolic acidosis.

CT abdomen and pelvis with IV contrast: preferred in a stable patient; identify the perforation source and whether contamination is contained or free.

Do not delay source control for CT in an unstable patient with convincing generalised peritonitis.

Keep fasting, establish large bore IV access and correct hypovolaemia with balanced crystalloid according to response.

Begin broad enteric Gram negative and anaerobic coverage immediately:

Ceftriaxone 2 g IV every 24 hours plus metronidazole 500 mg IV every 12 hours.

With septic shock, major contamination or healthcare associated infection:

Piperacillin tazobactam 4.5 g IV every 8 hours by extended infusion, adjusted for renal function.

Free perforation with diffuse peritonitis requires emergency source control.

Right sided perforation commonly requires right colectomy or ileocaecal resection.

Left sided perforation requires resection of the diseased segment. Primary anastomosis is reasonable in selected stable patients with good tissue perfusion. Severe shock, gross faecal contamination, major oedema or questionable perfusion favours diversion or staged reconstruction.

If perforation occurs through a colon cancer, perform an oncological resection when physiology permits.

A small iatrogenic colonoscopic perforation recognised immediately in a stable patient with minimal contamination can sometimes be closed endoscopically with clips or suturing and managed with fasting, IV antibiotics and close observation. Generalised peritonitis, failed closure or deterioration requires surgery.

After adequate source control of established intra abdominal infection, prolonged antibiotics are unnecessary. Approximately 4 days is generally adequate when the patient is recovering appropriately.