P063 Diverticular Colitis Preceding the Onset of Ulcerative Colitis, Case Report
Authors: Paredes Amenabar Carlos , Guzmán-Cárcamo Ana , López Goméz Jesús , Ramirez del Pilar Rodolfo , Trujillo de la Fuente Korely , Cortes Espinosa Tomas , Ramos Gómez Mayra , Aleman Abitia Dassaev , Navarro Gerrard Christian , Aguilar Hernandez Jhonatan 
Published: December 2019

INTRODUCTION:
Diverticular colitis (DC) is an inflammatory condition which affects only a segment of the colon and is associated to diverticula. It can share clinical characteristics with IBD suggesting an etiopathogenic relationship. This was a medically documented case of progression from DC to UC. To the best of our knowledge around 20 cases have been reported, none in Mexican patients.

CASE REPORT:
A 40-year-old male presented with self-limited cases of dysentery which did not respond to treatment. His initial blood work was remarkable: Leukocytes 9,000/mm3, Hb 15.7g/dL, erythrocyte sedimentation rate (ESR) 15 ml/h, C-reactive protein (CRP) 1.7mg/L negative P-ANCA, coprological study: negative for blood, pus and parasites. An initial colonoscopy reported an inflammatory colitis of unclear aetiology and pseudodiverticula in sigmoid colon. Biopsies of the ileum, rectum, sigmoid and colon reported a nonspecific inflammatory activity, emphasising that there were no criterium for IBD. Eight months later, the patient continued with the symptoms, laboratories were repeated: leukocytes 8,600/mm3, Hb 12.2 g/dL, ESR 40 ml/h, CRP 8.1 mg/L. Control colonoscopy reported a pancolitis compatible with UC and pseudodiverticula in sigmoid colon. Histopathology diagnosed a UC in an active phase.

DISCUSSION:
Diverticular Colitis is an endoscopically diagnosed pathology and in a pathognomonic way the pattern of inflammation of the colon does not affect the diverticular orifices. There are approximately 200 cases reported worldwide. The average age of presentation is 65 years, the male-female ratio is of 2:4. It typically presents with acute lower gastrointestinal bleeding and abdominal pain. The pathogenesis is uncertain, an overlap hypothesis supports a relationship between IBD and DC. One theory describes stress on the intestinal wall as a trigger for both diverticular disease and inflammation of the mucosa, which, in the genetically predisposed patient, can lead to the development of IBD. DC is classified into four subtypes: Type A or semilunar fold, type B similar to mild-moderate CUCI, type C similar to Crohn's disease, type D similar to severe CUCI. Gore S, and Shepherd N.A. reported 57 cases of CD where 6 progressed to UC in 6-24 months. To the best of our knowledge only 20 cases of progression have been reported, the last one in 2014 by Dr. Tatsuji Maeshiro, and none in Mexican patients.

CONCLUSION:
DC is a chronic and segmental inflammatory process of the mucosa associated with a diverticular disease. A physiopathogenic relationship between IBD and DC has been proposed. Reason why reporting and studying these cases could help resolve certain aspects of the physiopathologic route probably taken by this disease in a probable sequence of progression, analogue to the adenoma carcinoma sequence in colon cancer. Therefore, one could consider a closer follow-up in patients with diverticular colitis as they may progress to UC as in the previous case reported. This job has no conflict of interest.