Dame Julie Walters has opened up on her stage three bowel cancer diagnosis after she has been given the all clear.The legendary actress, 69, opened up on her secret health battle to Victoria Derbyshire, saying she initially thought doctors "must have made a mistake”, after she went for an appointment after suffering from stomach pain, heartburn and vomiting. She said: "I was still thinking, 'That's ridiculous, he must have made a mistake'.