What's really going on inside your stomach? In this program, Dr Michael Mosley offers up his own guts to find out. Using the latest in medical imagery and a tiny state of the art camera that he swallows at the start of the film, Michael takes viewers on a remarkable journey through his own internal system. At each stage he talks to medical experts and explains the amazing functions that happen without our conscious effort - and reveals a complexity and intelligence in the gut that science is only just beginning to uncover.