S1807 Diverticular Abscess Causing Bowel Obstruction

Abstract

INTRODUCTION: Emergency room visits for acute diverticulitis have increased 21% in the last few years. Although most of them are uncomplicated, an estimated 15% of all cases present with acute abdomen resulting in emergent surgery. The most common cause of complicated diverticulitis is bowel perforation which is usually diagnosed via computerized tomography (CT). A rare but more severe complication can include complete colonic obstruction secondary to diverticular abscess formation. CASE DESCRIPTION/METHODS: A 59 year-old female with a past medical history of recurrent diverticulitis presented with a three-day history of diffuse abdominal pain and distention associated with non-bloody emesis and non-bloody diarrhea. Her last diverticulitis flare was one year prior to presentation and resolved with antibiotics and supportive management. The patient denied prior colonoscopy and first-degree family members with colon cancer. On arrival, patient was afebrile and hemodynamically stable. Abdominal physical exam demonstrated a distended abdomen and diffuse tenderness along with decreased bowel sounds. Laboratory tests showed mild leukocytosis but were otherwise unremarkable. CT of the abdomen and pelvis with contrast demonstrated a 3 × 5 cm irregular mass at the junction of the descending colon and sigmoid colon suspicious for a malignant neoplasm along with colonic obstruction and sigmoid diverticulosis without fat stranding. Exploratory laparotomy found complete obstruction of the long segment of the thickened colon from which biopsies were obtained and she underwent left hemicolectomy with end-to-end anastomosis. Biopsy results showed diverticulitis with abscess, which was the etiology of the large bowel obstruction. The patient was placed on antibiotics and was discharged once she was able to have a bowel movement. DISCUSSION: Patients with known diverticulosis have a 10–25% chance of developing diverticulitis. Mortality from diverticular abscess is as high as 32% and can occur in remote areas via hematogenous spread of microorganisms through colonic mucosal defects. Severe bowel obstruction as with our patient, is rarer than partial obstruction which occurs due to wall edema and peripheral inflammation. Exploratory laparotomy is necessary and biopsy is crucial to definitively exclude colon cancer as CT imaging findings cannot solely include or exclude malignancy. It is important to evaluate for diverticular abscess in a patient with a history of diverticulitis in the setting of complete bowel obstruction.Figure 1.: 3 × 5cm Irregular mass seen at the junction of the Descending Colon and Sigmoid Colon.Figure 2.: Obstructing mass at the junction of the Sigmoid and Descending Colon.