Intracolonic lithiasis —a result of prenatal admixture of urine and meconium?

Three cases of intracolonic lithiasis are described, one in a fetus aborted at 19 weeks' gestation and two in premature infants delivered at 31 and at 32 weeks' gestation, respectively. The first infant died on the 2nd day of life while the other is currently doing well. The common features in all three were: radio-opaque intraluminal stones, imperforate anus with a fistula between the distal colon and the urinary tract, urinary outflow obstruction, and oligohydramnios. We postulate that the colonic calculi (commonly assumed to be intraluminal calcification) developed as a result of prenatal admixture of meconium and urine with distal urinary tract obstruction. It is important to distinguish this clinical entity from meconium peritonitis, which gives similar radiographic findings.