Focal active colitis as a predictor of inflammatory bowel disease: results from a single-center experience

The term focal active colitis (FAC) is conventionally used to describe the presence of isolated cryptitis, characterized by an inflammatory infiltrate consisting of intraepithelial neutrophils and/or neutrophils invading the lumen of the criptae, with no other microscopic alteration of the colonic mucosa and, in particular, without the presence of signs of chronic inflammation. To date, only four studies, including one conducted in a pediatric population, have been performed to evaluate the clinical significance of this disease. The aim of this retrospective study on prospectively-collected data is to evaluate the clinical implications of the focal active colitis, since there still remains a marked uncertainty regarding this topic and about how often such a diagnosis will presage a diagnosis of inflammatory bowel disease (IBD). Clinical, endoscopic, and pathological data were retrospectively reviewed from 30 patients with focal active colitis, who had no other diagnostic findings on colorectal biopsy and no history of chronic inflammatory bowel disease. The histological findings were correlated with clinical diagnoses. Thirty patients (11 males, 19 females; age 24-80 years, median 56 years) (0.5%) out of 5,600 undergoing colonoscopy between January 2012 and December 2016 presented a definitive diagnosis of FAC. Follow-up ranged from 6 to 60 months (median 24 months). At endoscopy, 19 patients (63%) had mild and non-specific changes, such as mild mucosal erythema, while 11 (37%) had normal findings. Eight patients were documented as having irritable bowel syndrome, while nine cases could be attributed to the effects of drugs, five presented FAC as incidental finding, one a diagnosis of infectious colitis, and seven a diagnosis of IBD (4 with Crohn’s disease). FAC was confirmed to be a more significant predictor of IBD than the previous literature would indicate, even if larger prospective studies, targeted to study this relationship, are needed to understand more clearly its clinical significance.