Fistula is an abnormal passage between a hollow or tubular organ and the body surface, or between two hollow or tubular organs

Arteriovenous fistula-

An abnormal connection between an artery and a vein.

Anal fistula-

An infected tunnel between the skin and the anus.

Obstetric fistula

-An abnormal connection between the rectum and the vagina.

Piles – Hemorrhoids-

Swollen and inflamed veins in the rectum and anus that cause discomfort and bleeding.Haemorrhoids are usually caused by straining during bowel movements, obesity or pregnancy.

Discomfort is a common symptom, especially during bowel movements or when sitting. Other symptoms include itching and bleeding.Pain in the anal region – can be even without straining in many cases.