Anal fistula is an abnormal opening that allows gastric fluids to be discharged through the lining of the stomach, intestines, or colon. The discharge can leak into other organs or the skin, causing infection.

External fistulas cause discharge through the skin. They are accompanied by other symptoms, including: • Abdominal pain • Painful bowel obstruction • Fever • Elevated white blood cell count With internal fistulas, patients may also experience the following symptoms: • Diarrhea • Rectal bleeding • Bloodstream infection, or sepsis • Poor absorption of nutrients and weight loss • Dehydration • Worsening of the underlying disease The most serious complication of GIF is sepsis, an illness in which the body has a severe response to bacteria. This condition may lead to dangerously low blood pressure, organ damage, and death.