Probing colons has never been this much fun. Japanese researchers have developed the world’s first self-propelled endoscopy device, a remote controlled tadpole-like camera that can “swim” through the digestive tack gathering imagery along the way. This kind of endoscopy isn’t wholly new, of course, but previous iterations of ingestible cameras relied on natural muscle contractions to move them through the body. The “Mermaid,” as it is known, simplifies the process by moving quickly through the digestive tract to its destination, whatever that point may be. To speed the process, it can be inserted into the digestive system at either end,...