Anal skin tags are just that, they are located right in/around the anus...
A fistula is an abnormal tunnel connecting two body cavities (such as the rectum and the vagina) or a body cavity to the skin (like the rectum to the outside of the body). One way a fistula may form is from an abscess -- a pocket of pus in the body. The abscess may be constantly filling with body fluids such as stool or urine, which prevents healing. Eventually the fistula breaks through to the skin, another body cavity, or an organ. Fistulas are more common in Crohn's disease than in ulcerative colitis. Approximately one quarter of people with Crohn's disease develop fistulas.
Types of Fistulas
Fistulas often occur in the area around the genitals and anus (known as the perineum). The four types of fistulas are:
Enterocutaneous: This type of fistula is from the intestine to the skin.
An enterocutaneous fistula may be a complication of surgery. It can be described as a passageway that progresses from the intestine to the surgery site and then to the skin.
Enteroenteric or Enterocolic: This is a fistula that involves the large or small intestine.
Enterovaginal: This is a fistula that goes to the vagina.
Enterovesicular: This type of fistula goes to the bladder. These fistulas may result in frequent urinary tract infections, or the passage of gas from the urethra during urination.
Symptoms of fistulas can include pain, fever, tenderness, itching, and generally feeling poorly. The fistula may also drain pus or a foul-smelling discharge. These symptoms vary based on the severity and location of the fistula.
Fistulas, depending on their location, can be diagnosed by some of the diagnostic tests often used in IBD. Barium enema, colonoscopy, sigmoidoscopy, or an upper endoscopy may be used.
I'd be going to see the doc ASAP.
My bum is broken....there's a big crack down the middle of it! LOL :)