Toilet Paper Can Disguise Cancer Sign: Doctor Blood in the toilet bowl could actually be red ink, he says By Neal Colgrass, Newser Staff Posted Jan 19, 2014 4:14 PM CST 41 comments Comments (Shutterstock) (Newser) – What looks like blood in your toilet bowl could actually be red ink seeping from your toilet paper, says colorectal surgeon Guy Nash—but he's still upset about it. That's because people who use toilet paper decorated in red may think they're seeing blood in the toilet when there isn't any, and vice versa. At stake is a possible colon-cancer diagnosis. "Those patients bleeding will miss real blood, and those not bleeding will report 'blood' in the toilet mistakenly," Nash tells LiveScience. "In my view, it is irresponsible of the makers to have not considered this," he said. But not all medical experts are on board: "I think it's nonsense," said a New York gastroenterologist who has never seen red blood confused with red-colored toilet paper. In any case, says Nash, "If someone sees blood, they should call their doctor, not panic, and have it appropriately evaluated." Even then, rectal bleeding is fairly common and is usually caused by a small anal tear or a swollen blood vessel—not colon cancer, notes WebMD.