Meconium peritonitis shown here as a greenish exudate overlying the serosal surfaces of the peritoneal cavity can complicate meconium ileus in utero, particularly in fetuses with cystic fibrosis. The bowel ruptures and leaks meconium, which produces a chemical peritonitis. Calcifications in the spilled meconium may be seen radiographically. Another complication of meconium ileus is volvulus. [Image contributed by Ted Pysher, MD, University of Utah]