Ileal Perforation

Ileal perforation is full thickness disruption of the ileum with enteric contamination of the peritoneal cavity.

Important causes include typhoid enteritis, tuberculosis, Crohn disease, bowel ischaemia, trauma, foreign bodies, obstruction and iatrogenic injury. Typhoid ileal perforation remains particularly relevant in regions where enteric fever is endemic.

The terminal ileum is commonly affected in typhoid because of prominent Peyer patches, with perforations usually occurring along the antimesenteric border.

Patients develop abdominal pain followed by localised or generalised peritonitis.

Features of established contamination include:

• Persistent tachycardia
• Abdominal guarding or rigidity
• Ileus and distension
• Fever
• Hypotension
• Oliguria
• Rising lactate or metabolic acidosis in advanced sepsis

Typhoid perforation may occur after several days of systemic febrile illness and may be multiple.

CT abdomen with IV contrast: identify ileal perforation, free contamination and any associated diseased segment.

In obvious generalised peritonitis with physiological deterioration, imaging must not delay source control.

Obtain full blood count, renal function, electrolytes, lactate, coagulation and crossmatch according to severity.

Blood cultures are particularly important when enteric fever is suspected and antibiotics have not already sterilised cultures.

Resuscitation and operative preparation occur simultaneously.

Keep fasting, establish large bore IV access, correct hypovolaemia and major electrolyte abnormalities and insert a urinary catheter in significant sepsis.

Start enteric Gram negative and anaerobic coverage.

A practical regimen is:

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

For septic shock, healthcare associated infection or substantial resistant organism risk:

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

Free ileal perforation with peritonitis requires surgery.

At operation, inspect the entire small bowel because more than one perforation may exist, particularly with typhoid disease.

A small isolated perforation with healthy surrounding bowel may be debrided and closed transversely.

Segmental ileal resection with primary anastomosis is preferred when perforations are multiple or clustered, the surrounding bowel is severely inflamed, the defect is large or tissue viability is uncertain.

Severe shock, gross contamination, poor tissue perfusion or major bowel oedema increases anastomotic failure risk and may justify temporary diversion or staged reconstruction.

When tuberculosis or Crohn disease is suspected, send tissue for histology and microbiology.

After adequate source control, routine prolonged treatment for secondary bacterial peritonitis is unnecessary. Approximately 4 days is usually sufficient, although treatment directed at the underlying disease such as enteric fever or tuberculosis follows its own required duration.