P073 Diagnostic Outcome of Patients With Non-Specific Colitis.

Background: Colitis describes inflammation in the colon and is classified into defined diseases: Inflammatory bowel disease (IBD), Microscopic colitis, Ischemic colitis and Infectious colitis. The clinical significance of non-specific colitis is unclear as there are limited analysis which report the issue. Notteghem et al. (1993) showed that of 104 patients with non-specific colitis, 52.3% had another episode of symptoms within 3 years. Of these patients 54% were diagnosed with ulcerative colitis, 33% with Crohn's disease, and 13% remained unclassified, suggesting that non-specific colitis could be undiagnosed IBD. The objective of this analysis is to determine the clinical course of non-specific colitis through colonoscopy and histologic findings.

Methods: Retrospective observational study with patients underwent colonoscopies during the period from 2009 to 2019, whose biopsies were reported as non-specific colitis.

Results: 24 patients (18 women and 6 men) with non-specific colitis undergoing follow-up by the Gastroenterology outpatient clinic were included. The most frequent indications for colonoscopy were abdominal pain (43.7%), blood in stools (26.8%), diarrhea (21.6%) and anemia (7.9%). The mean age was 56.5 years. During follow-up, patients had at least 2 colonoscopies and 4 biopsies per colonic segment. In the male population ascending colon cancer was later diagnosed in 16.7%, another 16.7% were diagnosed with nonspecific chronic ulcerative colitis, 33.3% with eosinophilic colitis, and the rest of the patients were diagnosed with non-specific colitis. From the female group, 5.6% had lymphocytic colitis, 5.6% eosinophilic colitis, 5.6% collagenous colitis, 5.6% Crohn's disease, 5.6% mixed irritable bowel syndrome, and the rest of the patients (72%) had biopsy report of non-specific colitis.

Conclusions: All patients with a histopathological diagnosis of non-specific colitis underwent a second colonoscopy with biopsy, which resulted in a definitive diagnosis of Crohn's disease in 5.6% of women and Ulcerative Colitis in 16.7% of men. This study comes to show that there is an important subgroup of patients who are underdiagnosed. We suggest that patients with non-specific colitis reported on a histopathology report must continue their follow-up by a specialized ward.