Original Report. Stercoral Colitis Leading to Fatal Peritonitis: CT Findings. Gastrointestinal Imaging Heffernan et al. CT of Stercoral Colitis

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1 Gastrointestinal Imaging Heffernan et al. CT of Stercoral Colitis Cathleen Heffernan 1 H. Leon Pachter 2 lec J. Megibow 1 Michael Macari 1 Hefferman C, Pachter HL, Megibow J, Macari M Received pril 21, 2004; accepted after revision July 6, Department of Radiology and bdominal Imaging, NYU Medical Center, 560 First ve., Ste. HW 207, New York, NY ddress correspondence to M. Macari (michael.macari@med.nyu.edu). 2 Department of Surgery, NYU Medical Center, New York, NY JR 2005;184: X/05/ merican Roentgen Ray Society Original Report Stercoral Colitis Leading to Fatal Peritonitis: CT Findings OJECTIVE. Stercoral colitis is an inflammatory process involving the colonic wall related to fecal impaction. Our purpose was to describe the imaging findings of stercoral colitis and ulceration and to emphasize the potential serious clinical implications of the condition. CONCLUSION. Fecal impaction may lead to ischemic pressure necrosis and subsequent colonic perforation. In the appropriate clinical setting, the imaging findings that should prompt the radiologist to consider this diagnosis are the presence of fecal impaction, focal colonic wall thickening, and adjacent stranding of the fat. If the fecal impaction is not promptly relieved, the condition can lead to colonic perforation, peritonitis, and patient demise. tercoral colitis is an inflammatory colitis related to increased S intraluminal pressure from impacted fecal material in the colon [1 3]. This rare condition, first reported in 1894, has been described primarily in the surgical and gastrointestinal literature [1 6]. s a result of the fecal impaction (a large mass of dry, hard stool that can develop because of chronic constipation), a focal pressure colitis may occur with ulceration resulting in colonic perforation. When stercoral colitis is associated with colonic perforation, a 35% mortality rate has been reported [1]. The sequence of events that can lead to fatal colonic perforation is the development of fecal impaction, which causes increased intraluminal and colonic wall pressure. If left untreated, ischemic ulceration and perforation can ensue. Very little has been published on stercoral colitis in the radiology literature [6]. Therefore, the purpose of this report is twofold: first, to show the imaging findings of surgically confirmed stercoral colitis associated with colonic perforation and, second, to emphasize the serious nature of this condition if not recognized and treated promptly. Materials and Methods Patients From October 2002 until pril 2003, four patients with surgically confirmed stercoral colitis were identified from the records of a weekly surgical morbidity and mortality conference. The patients included two men and two women with a mean age of 70 years (age range, years). CT Technique ll patients underwent CT examinations of the abdomen and pelvis before surgical exploration. CT examinations were performed with a HiSpeed dvantage or CTI scanner (GE Healthcare). Helical CT images were acquired using either 7- or 5-mm slice collimation; reconstruction interval of 6 or 4 mm, respectively; pitch of 1.5 2; 120 kv; and m. ll patients received oral administration of 800 ml of dilute (2%) water-soluble contrast material (Gastrografin [meglumine diatrizoate], ristol-meyers Squibb) beginning 1 hr before scanning. One patient received 150 ml of nonionic IV contrast material (iopromide [300 mg I/mL], erlex Laboratories), administered via a 22-gauge catheter inserted into an antecubital vein at a rate of 2 ml/sec using a power injector (Envision CT Injector, Medrad). Only two patients received oral contrast material. One patient underwent a second CT examination with oral and IV JR:184, pril

2 Heffernan et al. Fig year-old woman with stercoral colitis., xial CT scan obtained with oral contrast material at level of rectum shows fecal impaction. Note focal asymmetric wall thickening (black arrow) along posterior wall and presacral edema (white arrow)., Supine radiograph obtained next day shows intraperitoneal gas consistent with perforation. Note Rigler sign (arrows). contrast material, and one patient had follow-up CT performed without contrast material. Two patients underwent follow-up abdominal radiography after the initial CT examination. Imaging and Clinical Correlation n abdominal radiologist correlated the imaging findings with the operating surgeon. The location of the fecal impaction and presence of colitis, ulceration, and peritonitis were reviewed. The clinical outcome and time between imaging and surgical intervention of each patient were reviewed. Fig year-old woman with stercoral colitis., xial CT scan shows small perisigmoid abscess (arrow)., xial CT scan obtained 3 days later shows continued fecal impaction and increase in size of abscess (arrow). Surgical resection confirmed multiple stercoral ulcerations JR:184, pril 2005

3 CT of Stercoral Colitis Results Four patients were identified over a 6- month period who had surgically confirmed stercoral colitis leading to colonic perforation, peritonitis and sepsis, and, ultimately, death. The first patient was an 81-year-old woman with chronic constipation admitted for urinary tract infection. bdominal CT showed fecal impaction, focal thickening of the posterior aspect of the rectum, and fat stranding in the presacral space (Fig. 1). The patient was treated with enemas and manual disimpaction. The following day, an abdominal radiograph showed free air. t surgery, a focal perforation on the posterior wall of Fig year-old man with stercoral colitis., xial CT scan shows fecal impaction in sigmoid colon (long arrow). Note small bubble of extraluminal gas (short arrow)., xial CT scan obtained several centimeters cranial to shows fecal impaction (arrow) extending into descending colon with focal wall thickening (arrowhead) and several bubbles of extraluminal gas. Patient was treated with antibiotics. C, xial CT scan obtained next day shows portal venous gas (arrow). More caudal images (not shown) revealed pneumatosis. Intraoperative findings showed stercoral colitis with perforation and intestinal ischemia. the rectum was found consistent with stercoral ulceration. Despite fecal diversion and antibiotic therapy, the patient died secondary to sepsis. The second patient was an 80-year-old woman with a medical history of diverticulosis who presented with abdominal pain. CT showed fecal impaction with focal perforation and a 2- to 3-cm abscess (Fig. 2). fter antibiotic therapy, a repeat CT showed increase in abscess size to 7 cm. t surgery, sigmoid impaction and perforation with a large amount of intraperitoneal fecal material were present. The sigmoid colon was resected and a descending colostomy created. Pathology revealed multiple areas of perforation consistent with stercoral ulcerations. Two days later the patient died from sepsis. The third patient was an 80-year-old man who presented to the emergency department with severe abdominal pain. CT showed fecal impaction from the rectum to the descending colon with several bubbles of extraluminal gas and an adjacent focal area of wall thickening on the medial aspect of the descending colon (Fig. 3). The patient was treated conservatively with antibiotics. Three days later the patient complained of increasing abdominal pain, and a radiograph showed pneumatosis. CT confirmed pneumatosis and portal venous C JR:184, pril

4 Heffernan et al. gas. t surgery, stercoral perforation was identified along the medial aspect of the descending colon. The patient died 1 day later. The fourth patient was a 55-year-old man with paraplegia and a long history of constipation, who presented with increasing abdominal distention. Scout radiograph showed massive fecal impaction (Fig. 4). CT showed massive dilatation of the colon with free intraperitoneal gas. t surgery, stercoral perforation of the sigmoid colon with extensive intraperitoneal fecal contamination was identified. The patient died during surgery. Fig year-old man with stercoral colitis., Supine radiograph shows massive fecal impaction (arrows) and radiolucency in abdomen suggesting free air., xial CT scan obtained same day shows massive fecal impaction in sigmoid colon (arrowhead). Note extraluminal gas (arrow). Surgical findings confirmed stercoral colitis and perforation. Discussion The most common causes of colonic obstruction are adenocarcinoma, chronic diverticular disease, and volvulus [7]. Fecal impaction leading to colonic obstruction is seen primarily in the elderly, often those who live in nursing homes or, less often, young patients who are neurologically impaired. There is also an association with opiates, tricyclic antidepressants, and tranquilizers, most of which slow transit time through the bowel [8, 9]. pproximately 60% of patients who present with fecal impaction have a history of chronic constipation [4]. Fecal impaction can lead to stercoral colitis. The physiology of stercoral colitis is related to the development of a fecaloma, which is a conglomeration of dehydrated fecal material [1]. This causes distention of the colonic lumen and increases the pressure on the wall, which decreases blood supply to the area. If not treated aggressively with cathartics, enemas, and/or manual disimpaction, the ischemia can lead to ulceration and perforation [1 3]. This ulceration is typically round and can be multiple in up to 27% of cases [1]. Seventy-seven percent of stercoral ulcerations are found in the sigmoid colon or rectum [1]. This may reflect a number of factors including the decreasing water content in the stool as it progresses distally in the colon and the narrow diameter and high intraluminal pressures in the distal colon [1]. The three most common locations for stercoral ulceration are the anterior rectum just proximal to the peritoneal reflection, the antimesenteric border of the rectosigmoid junction, and the apex of the sigmoid colon [10]. Most cases are described as occurring on the antimesenteric side of the bowel wall. possible explanation is that the blood supply to the bowel enters on the mesenteric side and is relatively poor on the antimesenteric side, predisposing to ischemia. However, in our four cases, the ulceration was on the mesenteric side of the bowel in two patients. If the diagnosis is made early enough, aggressive bowel cleansing and disimpaction should be undertaken. This will decrease the pressure and lessen the likelihood of ulceration. lthough the diagnosis of fecal impaction is usually straightforward, several findings on CT should suggest associated stercoral colitis. First, in uncomplicated fecal impaction, the colon is distended and the wall is thin. We have noted that in cases of stercoral ulceration, focal thickening of the colonic wall may be present. This likely represents edema from the ischemia and ulceration. Second, stranding of the pericolonic fat in a segment that shows fecal impaction suggests colonic edema or ischemia. Third, presence of extraluminal bubbles of gas or an abscess suggests that perforation has already occurred. Intraoperative findings and histology confirm the diagnosis of stercoral ulceration [4]. Intraoperative findings include generalized peritonitis, colonic dilatation, edema of adjacent bowel wall, and ulcerations on the antimesenteric border usually measuring 1 10 cm, which are occasionally multiple. Grossly, the size and shape of the ulcerations are usually evident. If frank perforation occurs, fecal material is found within the peritoneal cavity in close proximity to the perforation site. Treatment is usually resection of the affected 1192 JR:184, pril 2005

5 CT of Stercoral Colitis bowel, colostomy, and Hartmann s pouch [1, 4]. Histologic findings include transmural necrosis, ulcer margins sharply demarcated without undermining, mild nonspecific inflammatory changes with mononuclear cells in lamina propria, and crypt abscesses. Our study had several limitations. First, we did not evaluate the total number of cases of stercoral colitis that occurred during this study. Clearly, fecal impaction is a common occurrence, and only a minority of these cases are associated with stercoral colitis. Second, we did not evaluate the specificity of the imaging findings of pericolonic fat stranding and colonic wall thickening in association with fecal impaction in the diagnosis of stercoral colitis. ecause most cases of uncomplicated stercoral colitis are successfully treated with disimpaction, a histologic diagnosis is not often obtained. In most cases of uncomplicated fecal impaction, the colon wall should be thin without adjacent fat stranding. The imaging findings of colonic wall thickening and pericolonic fat stranding suggest colitis. When associated with fecal impaction and in the right clinical setting, these findings should suggest stercoral colitis. In summary, fecal impaction is not an uncommon condition. Rarely, this can lead to stercoral colitis, a localized ischemia of the colon due to increased intraluminal pressure. If not treated promptly, focal ulceration can occur, leading to peritonitis, sepsis, and death. References 1. Serpell JW, Nicholls RJ. Stercoral perforation of the colon. r J Surg 1990;77: Grinvalsky HT, owerman CI. Stercoraceous ulcers of the colon: relatively neglected medical and surgical problem. JM 1959;171: Lal S, rown GN. Some unusual complications of fecal impaction. m J Proctol 1967;18: Mauer C, Renzulli P, Mazzuchelli L, Egger, Seiler C, uchler MW. Use of accurate diagnostic criteria may increase incidence of stercoral perforation of the colon. Dis Colon Rectum 2000;43: Wang S, Sutherlans JC. Colonic perforation secondary to fecal impaction. Dis Colon Rectum 1977;20: Rozenblit M, Cohen-Schwartz D, Wolf EL, Foxx MJ, renner S. Case reports: stercoral perforation of the sigmoid colon computed tomography findings. Clin Radiol 2000;55: Jackson R. The diagnosis of colonic obstruction. Dis Colon Rectum 1982;25: Hollingworth J, lexander-williams J. Non-steroidal anti-inflammatory drugs and stercoral perforation of the colon. nn R Coll Surg Engl 1991;73: Dubinsky I. Stercoral perforation of the colon: case report and review of the literature. J Emerg Med 1996;14: Tokunaga Y, Hata K, Nishitai R, Kaganoi J, Nanbu H, Ohsumi K. Spontaneous perforation of the rectum with possible stercoral etiology: report of a case and review of the literature. Surg Today 1998;28: JR:184, pril