Nephrocolocutaneous fistula from a staghorn calculus.

Fistula formation between the kidney, colon and the skin is an extremely rare complication arising from renal infections secondary to renal stone formation. During the 1980s, reports of nephrocolic fistulas, with or without involvement of the skin, were commonly caused by genitourinary tuberculosis. Due to improvements in diagnosis and specifically the development of anti-Koch's therapy, the incidence of nephrocolic or nephrocolocutaneous fistulas has become uncommon especially in developed countries.