Stercoral perforation of the colon is defined as "a perforation of the bowel due to pressure from faecal mass" [6]. It is not common, as complicated diverticulitis or an obstructing carcinoma more often undergo spontaneous perforation [8].
The first recorded stercoral perforation was by Berry in 1894. Since then, only 66 cases have been reported in the world literature [12]. However, the real incidence of this pathology cannot be conclusively ascertained because of the lack of a clear distinction between spontaneous perforation and idiopathic perforation, the latter including stercoral perforation.
Noussias [10] refers to spontaneous perforation as a perforation of the bowel caused by an evident colonic lesion, the term "idiopathic perforation" is therefore used in those cases where no evident pathology is present, as it develops in an apparently normal colon.
A 38-year old man with a mental handicap was admitted to hospital in April 1987. The patient came from an asylum. He had always been in good health until a few days before admission when he began to have severe vomiting associated with generalised abdominal colic and constipation. On the day of admission the patient showed clouded sensorium and peritonitis facies; his temperature was 39°C; pulse rate 130 beats/min.; blood pressure 100/60 mmHg. The abdomen was tender and there were no bowel sounds. Rectal examination showed an empty ampulla and a tender Douglas pouch. Laboratory data included haemoconcentration (Ht 46%; Hb 15g/dl; GB 15,700; creatinine 2,4 mg/dl; azotaemia: 60 mg/dU. Plain radiography of the abdomen showed the presence of free gas in the subdisphragmatic areas. The patient then underwent operation.
A midline laparotomy was performed. On opening the peritoneum, gas and purulent malodorous fluid was found in the whole peritoneal cavity. There was a perforation about 8 mm in diameter in the descending colon, from which a faecalome protruded. The transverse colon, part of the descending and ascending colon and an extended area of the sigmoid colon contained a large number of brown hard faecalomas measuring roughly 9x6 cm each. A 30 cm resection of the descending colon was performed, which was followed after mobilisation of the left colonic flexure by a left colostomy and a distal mucous fistula, all faecalomas proximal and distal to the perforation were removed manually. Intraoperative peritoneal lavage with a saline solution and antibiotics followed. The resected colon showed extensive ulceration above and below the perforation. Histologic examination showed typical decubital ulcers without chronic infliltration. In the first 8 hours after the operation, an infusion of about 6 lt of fluid was given to restore adequate diuresis. The postoperative period was complicated by a left pleural effusion, which resolved after medical treatment.
Many irrigations of the distal colonic stump were performed. The patient was discharged 20 days after the operation. Bowel continuity was restored after six months.
Chronic constipation, the frequent ingestion of substances such as antacids (aluminium hydroxide) [2], codeine [4], amitriptyline [1], tranquillizers [3,13], corticosteroids [1], clay mixture and paper in people with a pica for paper [5] may lead to stercoral perforation. However, it must be emphasised that faecalomas, which may cause a primary ischaemic necrosis, may persist in spite of an apparently normal bowel function. Of the 66 patients [12] reviewed, only 39 had a history of chronic constipation before perforation. 23% came from asylums or nursing homes [12]. The mean age was 60 years, with a range from 16 to 89 years [12]. The 66 cases reported in the literature and our case show that preoperative diagnosis of stercoral perforation is rare (17/66 cases) [12], because the incidence is low and the symptoms not clearly detectable. All patients presented features of acute abdominal conditions with diffuse peritonitis (80%) or faecal peritonitis (20%). The most common site for the perforation was the sigmoid colon (47%), followed by the rectum (30%), caecum (9%), transverse colon (7%), and descending colon (5%). All perforations except one occurred on the antimesenteric border of the colon. Perforations were single in 79% and multiple in 2196 of the patients. A preoperative aetiological diagnosis is purely academic considering the seriousness of the clinical picture of faecal peritonitis, which is characterised by a high mortality rate when not treated by prompt surgery. Of the 66 patients 52 underwent surgical intervention with a 35% mortality.The mortality according to the type of operative treatment was, 57% after the closure of the perforation and proximal colostomy, 4396 after exteriorisation and 32% after exteriorisation and colon resection. The operation with the lowest mortality seems to be colon resection with proximal colostomy and Hartmann's procedure with a distal mucous fistula. In our opinion, although the choice of operation depends on where and when the perforation occurs and on the technical skill of the surgeon [7], a successful result depends also on other elements, such as: a) manual evacuation of the faecalomas which otherwise could make postoperative bowel movement difficult; b) colon resection, including all the decubitus ulcers, which are frequently found in the area surrounding the perforation.
