A fistula is an abnormal connection or tunnel that forms between two body parts, such as organs, blood vessels, or intestines. Fistulas often develop due to infections, inflammation, injury, or complications from surgery or diseases like Crohn’s disease. They can cause discomfort, discharge, and serious health complications if left untreated.

Types of Fistula

1. Anal/Perianal Fistula
   The most common type, it forms between the anal canal and the skin near the anus. Often results from an infected anal gland or abscess.

2. Rectovaginal Fistula
   Occurs between the rectum and vagina, leading to fecal matter or gas passing through the vagina. Usually caused by childbirth trauma, surgery, or Crohn’s disease.

3. Vesicovaginal Fistula
   A connection between the bladder and vagina, often resulting in continuous leakage of urine. May be caused by prolonged labor, surgery, or radiation therapy.

4. Enterocutaneous Fistula
   This type connects the intestine to the skin, allowing intestinal contents to leak out. Usually a complication of abdominal surgery or severe bowel disease.

5. Colovesical Fistula
   A rare type connecting the colon and bladder, which may cause recurrent urinary tract infections or fecal matter in urine.

6. Arteriovenous Fistula
   An abnormal connection between an artery and a vein. This may be congenital or surgically created for dialysis access.