Red Out

A homogeneous red-orange colour seen by GI endoscopy when the intestinal mucosa directly covers the endoscope’s lens, allowing only the passage of light across the blood vessel-rich mucosa; red-out can be corrected by a puff of air to push the mucosa away from the visual field
References in periodicals archive ?
I received several replies to my article a couple of weeks back about Red Out.
He reminded me of her feat when the handicapper at the time thought she had won enough, so within 10 days Red Out had to run three times.
Thanks Andy for the photo of Red Out and for the press clippings, I will treasure them.