Anal fissures are cracks of skin on the lining of the opening of the anus.In some people they cause pain during bowel movements but many peopledo not feel any pain or just slight pain. Bright red blood on the toilet paperafter wiping is usually indicative of a fissure.A major cause of a perianal abscess is when these fissures get infected.And after these abscesses open (either on their own or surgical lancing),50 to 67% of the time these abscesses form into perianal fistulas.Fistulas continiously seep pus out of an external opening of the abscessuntil surgery is performed. In almost all cases, surgery is required to close a fistula. The surgery can be extremely complicated as fistulassometimes tract through the sphincter muscle. Because of this, many peoplewith fistulas are forced to undergo multiple surgeries. How to avoid this problem? Check your toilet paper after wiping. If you see bright red blood, seek treatment for the fissure. Treatmentis usually a cream.