Uncomplicated sigmoid diverticulitis

Case Discussion

This case presents a relatively young patient with an episode of acute sigmoid diverticulitis. Given that this condition generally occurs in older patients, this presentation is atypical. However, the incidence rates of diverticulitis in younger patients have been found to be increasing in the last few decades. Given that this patient was a woman of childbearing age with left lower quadrant pain and elevated white blood cell count, the differential diagnoses for this patient prior to imaging was sigmoid diverticulitis, ruptured ectopic pregnancy, and tubo-ovarian abscess.

Colonic diverticulosis refers to the presence of multiple outpouchings of the colonic wall. These outpouchings typically form at weak points in the colonic wall, likely due to a combination of increased intraluminal pressure secondary to straining and decreased elasticity of the colonic wall with age. Sigmoid diverticulitis refers to the inflammation or infection of diverticula in the sigmoid colon. Clinical suspicion for sigmoid diverticulitis should be raised when a patient presents with LLQ pain, fever, and an elevated WBC. The preferred initial imaging modality for suspected diverticulitis is CT abdomen/pelvis with contrast. Supportive CT findings for the diagnosis of sigmoid diverticulitis include colonic outpouchings, bowel wall thickening beyond 3 cm, surrounding edema, and peridiverticular fat stranding. Colonic diverticulitis can be associated with several complications including perforation (resulting in pneumoperitoneum), intestinal obstruction (manifesting on imaging as dilated intestinal loops and air-fluid levels), and peridiverticular abscess (presenting on CT as hypodense collections with peripheral contrast enhancement). Screening colonoscopy is recommended 6-8 weeks after the resolution of a first-time episode of uncomplicated diverticulitis or any episode of complicated diverticulitis to assess the extent of diverticulitis and rule out malignancy.