A rare but potentially fatal disease of colon

Case history

A paraplegic patient in their 50s was admitted to our emergency department with abdominal pain, nausea, and vomiting. On physical examination, there was a markedly distended abdomen with diffuse tenderness and hard stool on the rectal examination. Laboratory tests revealed an elevation of white blood cell count (12.4 × 10³ per cubic millimeter). Plain abdominal radiography showed dilatation of the large bowel. Contrast-enhanced computed tomography (CT) was performed to determine the cause of colonic dilatation.

Questions

1. What are the CT findings? (Figures 1 and 2)

2. What is the radiological diagnosis?

3. Why emergency physician and radiologist should be aware of this colonic pathology?

Figure 1.

Axial CT image shows calcified fecaloma (asterisk) and thickening of the rectal wall (arrows).

Figure 2.

Axial CT image illustrates markedly distended rectosigmoid colon filled with fecaloma (asterisk) and associated fat stranding (arrows) adjacent to the thickened rectal wall.

Answers

1. Both are axial CT images. Figure 1 shows calcified fecal impaction (asterisk) and thickening of the rectal wall (arrows). Figure 2 shows markedly distended rectosigmoid colon with a fecaloma (asterisk) and associated fat stranding (arrows) adjacent to the thickened rectal wall.

2. Stercoral colitis.

3. Stercoral colitis is a rare but life-threatening complication of fecal impaction. This inflammatory colitis mainly affects elderly or bedridden patients with chronic constipation. Other risk factors include long-term use of opiates or tricyclic antidepressants, diabetic enteropathy, and hypothyroidism.^1,2 The etiology of stercoral colitis is related to increased intraluminal pressure from impacted fecaloma in the large bowel. As a result of the fecal impaction, the large bowel becomes distended. Bowel ischemia results when intraluminal pressure becomes greater than capillary perfusion pressure within the bowel.^3,4

Stercoral colitis needs to be recognized early and treated properly to avoid the potentially fatal complications such as bowel perforation and peritonitis. It should be considered in the differential diagnosis of abdominal pain in patients with chronic constipation. A high level of suspicion and prompt imaging are extremely crucial in the accurate diagnosis of stercoral colitis.