S1820 Diverticulitis in the Time of COVID-19: Acute Diverticulitis Complicated by Colo-Colonic Fistula

Abstract

INTRODUCTION: Colo-colonic fistula is a rare complication of diverticulitis. We present a case of acute diverticulitis with delayed presentation due to COVID 19, complicated by diverticular abscess and colo-colonic fistula in the setting of delayed treatment with oral antibiotics. CASE DESCRIPTION/METHODS: An 82 year old male presented with a 3 week history of diffuse abdominal pain, fever, nausea, anorexia and 12 lbs weight loss. He reported narrow stools without hematochezia. There were no other symptoms or prior episodes. Diverticulosis was present on his colonoscopy 5 years earlier. On examination his abdomen was mildly tender throughout without guarding or rebound. Stool was guaiac negative. Lab work revealed WBC of 19 K/uL, and a microcytic anemia with Hb 10.6 g/dL. Computed tomography (CT) revealed sigmoid diverticulitis with extraluminal air loculations and a 3 cm pericolonic abscess. Because of the Coronavirus pandemic, the patient requested outpatient therapy and was started on oral Ciprofloxacin and Metronidazole. He was followed weekly via telehealth with improvement in symptoms except for mild intermittent abdominal pain. Follow up CT revealed fistulization of the previously noted abscess to distal sigmoid colon, producing an inverted U-shaped fistulous tract from proximal to distal sigmoid. Labs revealed resolving leukocytosis and stable anemia. He completed 4 weeks of oral antibiotics and declined surgery. DISCUSSION: The Coronavirus pandemic has overt direct health consequences, as well as secondary and tertiary consequences. Our patient presented, after a 3 week interval without treatment, with localized sepsis and a 3 cm abscess. This would normally be treated with parenteral antibiotics and possibly percutaneous drainage or surgical intervention. Due to concerns regarding Coronavirus exposure in the hospital, he opted for treatment with oral antibiotics alone after a delayed presentation. Consequently, the abscess decompressed into a distal segment of sigmoid colon, producing a colo-colonic fistula. Colo-colonic fistulae are a rare complication of diverticulitis compared to colo-vesical, colo-vaginal, colo-enteric and colo-cutaneous types. Literature on colo-colonic fistulae is sparse in the past 50 years, perhaps because antibiotic therapy is often begun at the onset of symptoms. This case demonstrates an uncommon complication of a common condition which may not have occurred if not for the Coronavirus pandemic.Figure 1.: Sagittal CT showing U shaped fistula of sigmoid colon.