What's the difference between a shunt and fistula?

Fistula vs shunt. Basically, fistulas are natural occurring, abnormal communications between structures (e.g. Between the trachea & the esophagus or between the bladder & the vagina) & shunts are man made communications between structures (e.g. Between an artery & a vein for dialysis or between a cerebral ventricle & the peritoneal cavity for removing excess cerebrospinal fluid in hydrocephalus).