Final answer:
A fistula is an abnormal passage between two organs or from an organ to a body opening. It is a connection that forms between two tissues that are not normally connected.
Step-by-step explanation:
A fistula is an abnormal passage between two organs or from an organ to a body opening. It is a connection that forms between two tissues that are not normally connected. For example, an arteriovenous fistula is an abnormal connection between an artery and a vein. Fistulas can occur as a result of surgery, injury, or an infection.
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