(1) Blood tests (i) Leukocytosis (ii) Neutrophilia (2) Inflammatory markers (i) High levels of C-reactive protein (ii) High levels of procalcitonin (3) Abdominal X-ray (i) Pneumoperitoneum (ii) Pneumoretroperitoneum (iii) Subcutaneous emphysema (4) Chest X-ray (i) Pneumothorax (ii) Pneumomediastinum (iii) Subcutaneous emphysema (5) Abdominal CT scan with oral and rectal contrast (i) Typical features of peritonitis (ii) Free intra-abdominal gas (iii) Free intra-abdominal fluid (iv) Peritoneal and mesenteric thickening
(1) Conservative treatment (intravenous fluids, bowel rest, and intravenous administration of broad-spectrum antibiotics) (i) Patients in good general conditions (ii) No signs of generalized peritonitis (iii) Perforation unnoticed by the endoscopist (iv) Good degree of bowel preparation (v) Early detection of the CP (vi) No underlying disease requiring surgery (2) Surgery (simple closure with sutures) (i) Small CP < 50% of bowel circumference (ii) No fecal contamination (iii) No concomitant intestinal pathology requiring bowel resection (3) Colonic resection (Hartmann’s versus colectomy and primary anastomosis) (i) Depending on the grade of intra-abdominal contamination and the general condition of the patient (4) Endoscopic clipping followed by conservative treatment (i) Early recognition of the CP (ii) Small CP < 10 mm (iii) No signs of peritonitis (iv) Good bowel preparation
