At best, I can imagine this being a rectum cancer check, not a colon cancer check - the colon is around 1.6-1.7m long. Even the rectum is longer than a typical

At best, I can imagine this being a rectum cancer check, not a colon cancer check - the colon is around 1.6-1.7m long. Even the rectum is longer than a typical finger (typically ~12cm long according to Wikipedia).