Intestinal perforation is a full-thickness breach in the wall of the small or large bowel, resulting in leakage of intestinal contents including bacteria, faecal material and digestive enzymes into the sterile peritoneal cavity. It constitutes one of the most serious abdominal surgical emergencies, rapidly leading to chemical peritonitis followed by bacterial peritonitis and, if untreated, life-threatening septic shock and multi-organ failure. Common causes include perforated peptic ulcer, acute appendicitis, diverticular disease, strangulated bowel obstruction, Crohn's disease, typhoid fever, abdominal trauma and iatrogenic injury during endoscopic procedures. The severity of the clinical picture depends on the site of perforation, the volume of contamination and the time elapsed before surgical intervention.
Symptoms
The clinical presentation is typically acute and dramatic. Patients develop sudden-onset, severe abdominal pain classically described as an agonising, knife-like pain that begins at the site of perforation and rapidly spreads to involve the entire abdomen as peritoneal soiling progresses. Abdominal rigidity the so-called "board-like abdomen" is the hallmark examination finding, reflecting involuntary guarding of the peritoneum in response to chemical and bacterial irritation. Rebound tenderness is universally present. Patients appear acutely unwell with fever, tachycardia, hypotension and pallor. Nausea, vomiting and complete cessation of bowel activity accompany the picture. As the condition advances without treatment, signs of septic shock including confusion, cold peripheries and cardiovascular collapse develop rapidly, making early recognition critical.
Diagnosis
The diagnosis is primarily clinical, supported by urgent investigations. Erect chest X-ray is the first and most important radiological investigation, demonstrating free gas under the diaphragm (pneumoperitoneum) in the majority of cases a pathognomonic finding of hollow viscus perforation. CT scan of the abdomen and pelvis with contrast is the gold standard, confirming free air and free fluid, identifying the likely site of perforation and detecting associated complications such as abscess formation or bowel ischaemia. Blood investigations reveal a raised white cell count, elevated CRP, and metabolic acidosis with raised lactate in advanced cases all indicating the degree of systemic sepsis and guiding resuscitation priorities.
Treatment
Immediate resuscitation runs in parallel with surgical planning intravenous fluids, broad-spectrum intravenous antibiotics, analgesia, nasogastric decompression and urinary catheterisation are instituted without delay. Emergency surgery is the definitive treatment in virtually all cases. The operative approach depends on the cause and site of perforation: a perforated peptic ulcer is managed by omental patch repair (Graham's patch); perforated appendicitis by appendicectomy with peritoneal lavage; colonic perforation from diverticular disease or malignancy typically requires bowel resection with a Hartmann's procedure forming a temporary end colostomy to avoid a primary anastomosis in a contaminated field. Thorough peritoneal washout is performed in all cases to reduce the bacterial load and minimise the risk of post-operative abscess formation. The timing of surgery is the single most critical determinant of survival each hour of delay significantly increases mortality and perforation presenting beyond 24 hours carries a substantially higher risk of irreversible septic complications and death.