Two weeks ago I was admitted to hospital for emergency surgery when I developed a perianal abcess and serious infection. I have suffered with chronic diarrhoea for about 18 months now and the consultant in hospital believes this is linked with the abscess.I am concerned today though as for the last three days I am passing black tar-like stools every time I go to the toilet. This has never happened before and I am now worried that I am bleeding internally. Could the black stools be linked with the abscess or is it something else? Should I see a doctor?Thanks in advance for any help.