A higher diagnostic profile is possible for microscopic colitis: authors’ reply

Abstract

Sirs, We thank Cammarota et al. for their comments and interest in our article. We agree that efforts to facilitate and improve the diagnosis of collagenous colitis (CC) are essential. In general, the colonic mucosa is macroscopically normal in CC, but about 30 % of the patients have minor mucosal abnormalities, which easily may be overlooked.1 The histopathological changes are most prominent in the proximal colon and may be absent in the sigmoid or rectum.2, 3 As Cammarota et al. point out, endoscopic ultrasonography and confocal endomicroscopy have been applied in CC, though in a limited number of patients so far. In addition to these new interesting techniques, chromoendoscopy by vital staining with indigo carmine of the colonic mucosa during colonoscopy has been used in a few patients with CC to enhance the macroscopic assessment.4, 5 An uneven and coarse surface with a different staining pattern has been reported in CC compared with the normal mucosa. Whether this staining technique or the other mentioned endoscopic techniques would increase the diagnostic yield of mucosal biopsies in CC remains to be proved. Until these interesting new techniques have been tested in larger prospective studies we have to rely on a high clinical awareness of the disorder by the endoscopist. Currently, a pan-colonoscopy with multiple biopsies throughout the colon still remains the best diagnostic method.