I have a cut that wont heal

Patient: I have a cut that wont heal

Symptoms: I have a cut near my rectum, and has been there for a few weeks now, I visited my local doctor and he explained it was nothing more than a cut and gave me some dressings to keep it dry and stop it from rubbing against anything. Ive followed his instructions for over two weeks and seen no improvement. The cut bleeds and occasionally there is some pus in the blood. How can I get this wound to go away?