Background: Bright red linear marks in the right colon are occasionally seen but have never been described in the medical literature. We have termed this finding "cat scratch" colon.
Methods: This was a prospective examination of 8277 colonoscopies at a single endoscopy center in a private practice setting. All cases of cat scratch colon were biopsied, and the results read by two pathologists.
Results: A total of 21 cases of cat scratch colon were identified, all in the ascending colon and cecum, with a prevalence of 0.25%. The majority of cases were in women. Although the colon was histologically normal in most cases, there was a significantly higher proportion of collagenous colitis in patients with cat scratch colon compared with the total cohort (14% vs. 0.15%).
Conclusions: The prevalence of bright red linear markings (cat scratch colon) in the cecum and ascending colon is 0.25%. These markings appear to be superficial breaks in the mucosa possibly secondary to barotrauma. Patients tend to be older women with higher proportion of collagenous colitis.