Right-sided diverticular disease, including cecal diverticulum, is a relatively uncommon occurrence in Western cultures when compared to left-sided diverticular disease [1],[2],[3]. Even more rare than this is the perforation of these diverticulum due to stercoral colitis [4],[5],[6]. We report the case of an 83-year-old man who presented to the Emergency Department with a relatively brief history of periumbilical and right lower quadrant pain, associated with nausea and low-grade fevers, with a computer tomography (CT) scan demonstrating perforation of a large cecal diverticulum requiring acute surgical management, with positive patient outcomes.

An 83-year-old male with a known background history of asthma, chronic obstructive airways disease (COAD), gastroesophageal reflux disease (GORD), gout and osteoarthritis, was brought in by ambulance to the Emergency Department with a 30-hour history of worsening abdominal pain and bloating, associated with nausea and retching. He reported that his bowels were opening as “normal,” however there was noted to have been a 2-week history of functional decline. On examination he was found to be tachycardic with a heart rate of 106 beats per minute, and febrile to 37.8°C; however, the rest of his observations were noted to be within normal limits. His abdomen was distended and tender in both the periumbilical region and the right lower quadrant with guarding and percussion tenderness. Chest and abdominal X-rays were performed which were normal in appearance. Blood tests demonstrated a leukocytosis, an elevated C-reactive protein and a mild acute kidney injury (AKI). The remainder of the bloods were unremarkable. Computed tomography scan was then performed which demonstrated extensive inflammatory changes centered over the proximal ascending colon, with bowel wall thickening adjacent to the ileocecal valve, as well as within the caecum and ascending colon. There was noted to be a focal outpouching on the medial aspect of the involved ascending colon, likely a large diverticulum, which measured 41 × 33 mm and contained feculent material (Figure 1). There was extensive surrounding fat stranding and mesenteric congestion/edema. Multiple gas locules were present to suggest perforation (Figure 2 and Figure 3). There was free fluid within the right iliac fossa and pelvis. The remaining small bowel, large bowel, and the appendix were normal.

The patient was taken to the operating theater on the day of admission where an exploratory laparotomy was undertaken through a midline laparotomy incision. The findings were a perforation of a wide mouthed large cecal diverticulum due to fecal impaction causing necrosis (Figure 4). There was localized fecal contamination and pus in the right iliac fossa and the pelvis. Another adjacent large diverticulum with evidence of fecal impaction was also noted, with features of wall necrosis without perforation (Figure 5). The small bowel was noted to be normal, with no obvious distal colonic obstruction. The right hemi-colon was mobilized, with ligation and division of the ileocolic vessels and a limited right hemicolectomy with a stapled ileo-ascending colon anastomosis between proximal margin, 8cm from the ileocolic junction and the mid-ascending colon was performed. A 19 French Blake drain was placed into the pelvis prior to closure.

The patient was admitted to the intensive care unit (ICU) for 48-hours post-operatively with an inotrope requirement that gradually improved. His recovery was complicated by a post-operative ileus which resolved on post-operative day 5, and he was managed with total parenteral nutrition (TPN) until his diet could be upgraded from clear fluids on post-operative day 6. Intra-abdominal swab grew Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca, which was treated with antibiotics for seven days total. He was later discharged to an inpatient rehabilitation unit.

Surgical pathology demonstrated diverticular disease with perforated diverticulum and peritonitis with no evidence of malignancy. The diverticulum associated with perforation demonstrated mucosal/mural ischemia and transmural inflammation. The appendix and sampled lymph node were unremarkable.

Diverticula are outpouchings of bowel wall which may be congenital or may form in areas of weakness, usually due to increased intraluminal pressure or trauma where the vasa recta penetrate the bowel wall [7]. True diverticula involve all three layers of bowel wall, whereas pseudodiverticula typically do not involve the muscular layer and are more prone to inflammation and perforation, as seen with sigmoid diverticulitis [7]. While left-sided colonic diverticular disease is common in Western countries and is largely thought to be related to diet, right-sided disease is considered rare [1],[2],[3]. They represent approximately 3.6% of all colonic diverticula and are more common in Asian populations [8],[9]. The majority of cecal diverticula tend to arise from the anterior aspect of the caecum, and right-sided diverticulitis typically affects a younger population with the average age being 43.6 years and a male to female ratio of 3:2—most commonly being mistaken for acute appendicitis on presentation [9].

Stercoral colitis with perforation of the colon is uncommon (3.2% of all colonic perforations) and can be life-threatening, with delayed diagnosis often resulting in complications, including death [4],[5],[10]. Diverticular diseases and stercoral colitis share similar pathophysiology and may coexist, and it can be difficult to decide the cause of perforation in patients with both diverticulosis and stercoral colitis [4],[10]. Long-standing constipation is associated with the formation of fecalomas, such as that which occur in the aging population, which exerts persistent pressure directly on the bowel wall, leading to ischemic necrosis and subsequent stercoral perforation [4],[5],[6][10]. The most commonly affected areas are the sigmoid and descending colon, as well as the rectum (up to 90% of cases). Stercoral perforation of the cecum is rare, accounting for only 5.9% of all stercoral perforation cases, with few case reports in the literature—particularly due to the more liquid nature of the stool passing through this area [4],[10],[11],[12].

Clinical presentation of cecal diverticulitis or perforation of a cecal diverticulum most commonly includes right lower quadrant pain (although can include more generalized peritonitis), low grade fevers, nausea, and vomiting [3],[10]. There may be the presence of a palpable abdominal mass where fecalomas are present [10]. Computed tomography is the imaging modality of choice in diagnosis of right-sided colonic diverticular disease with 98% sensitivity and specificity, particularly in differentiating the presentation from acute appendicitis [2],[7],[9]. Additionally, findings on CT scans which may indicate a stercoral perforation include the presence of free gas (including extraluminal gas locules), the presence of fecal impaction or fecaloma, thickening of the involved colonic wall, and surrounding fat-stranding [5],[10].

In cases of severe cecal diverticulitis or perforation of a cecal diverticulum from causes such as stercoral colitis, surgical treatment methods like the ileocecal resection or right hemicolectomy may be required [2],[6][9]. Where the underlying pathology is unclear, including when malignancy cannot be excluded, or when there is extensive inflammation, a right hemicolectomy is the suggested approach [8],[9]. Peritoneal fluid culture in stercoral perforation is typically positive for gram-negative and anaerobic organisms, so patients should be treated with antibiotics effective against these organisms, in addition to the definitive surgical intervention [10].

The intraoperative findings of stercoral perforation including of diverticulum comprise dilatation of the affected colon, presence of fecalomas or hard stool, edema of the bowel wall, and ulceration—typically on the antimesenteric border and peritonitis subsequent to the perforation [4],[10]. Histopathological findings are generally those of ischemic necrosis and general inflammatory changes [10]. In our case the fecalomas were confined to the large diverticula so there were no obvious colonic dilatation or ulcerations on the antimesenteric border noted. The appearance of the necrotic patches in the two wide mouthed large diverticula with the presence of firm stool favors stercoral perforation.

Cecal diverticular disease is rare in the Caucasian population, and it is often misdiagnosed on presentation as acute appendicitis; however, it can be readily distinguished on imaging such as CT scan. Perforation is rare, particularly when due to stercoral colitis, but should be considered in the context of the systemically unwell older patient with a history of constipation.