Sir.—Most studies of intra-abdominal infections, including intra-abdominal abscesses, have been carried out in adults.1 Polymicrobial aerobic and an-aerobic flora were found to predominate in the majority of patients with intra-abdominal infections after perforation of the viscus, with an average of five isolates in an infection site. Studies of intra-abdominal infections in children investigated only the microbiology of peritonitis after appendicitis2 and did not report the bacteriology of intra-abdominal abscesses.
The microbiology of intra-abdominal abscesses in pediatric patients was evaluated in 15 children (nine male patients). Patients' ages ranged from 10 months to 15 years (average, 9 years), and their abscesses were drained through open surgery in Washington, DC, area hospitals between June 1978 and April 1985. The factors predisposing to infection were ruptured appendix (eight patients), trauma (three patients), Crohn's disease (two patients), intestinal surgery (one patient), and rupture of the viscus (one patient). Nine patients had