1627 Segmental Colitis Associated With Diverticulosis: An Emerging Entity Among the Non-Specific Colitis

Abstract

INTRODUCTION: An 86 y/o male with diverticulosis and hypertension, arrived at the ER due to intermittent episodes of bright rectal bleeding associated with lower quadrant abdominal pain since 3 weeks ago. Laboratories without anemia, leukocytosis, eosinophilia or any other abnormality. CT abd/pelvic revealed a segmental area of concentric mural thickening and narrowing of the lumen of the sigmoid colon, concerning for a mass. No prior colonoscopies or GI alarming features. GI service consulted for diagnostic endoscopic procedure. CASE DESCRIPTION/METHODS: Sigmoidoscopy was remarkable for severe diverticular disease of the rectal mucosa with associated significant erythema, exudative material and loss of vascular pattern consistent with an inflammatory process. At 20 cm from the anal verge, a luminal narrowing covering > 90% of the lumen extended up to 27 cm. Pathology report from the area of obstruction showed acute over chronic inflammation without granulomas, microorganisms or dysplasia. He was started on rectal mesalamine and a 14-day course of oral antibiotics (metronidazole and ciprofloxacin). Surgery service consulted which agreed with medical management. Within two weeks after completion of antibiotics, colonoscopy was performed revealing marked improvement of the luminal narrowing evidenced in the previous colonoscopy at 20cm, including less degree of inflammation and fewer loss of vascular pattern among the segmental area within multiple diverticuli. Biopsies taken from the same narrowing were remarkable for chronic inflammation without dysplasia. All findings were consistent with segmental colitis associated with diverticulosis (SCAD). DISCUSSION: SCAD is an inflammatory process that affects colonic luminal mucosa in areas that are affected by diverticulosis. The prevalence is 1.5 – 11.4% among those with diverticular disease. The pathogenesis of SCAD is unclear. The clinical presentation is not specific and thus similar to other pathologies, including inflammatory bowel disease, for which makes this condition difficult to diagnose. There are currently no guidelines for its management. It is frequently based on the administration of salicylates, antibiotics and surgical intervention for refractory cases. Currently it is unclear if SCAD is in fact a spectrum of IBD or if it is itself a separate entity. The rarity of SCAD supports the claim that further research is needed to better understand the disease and thus improve its management and clinical outcomes.