To the Editor: Increased local mucosal production of tumor necrosis factor-α (TNF-α) was reported, especially in inflammatory bowel disease, and it was shown that TNF-α concentrations in stool correlated with disease activity (1, 2). Tumor necrosis factor-α in stool seems to come from two sources: from leakage across the epithelium after local synthesis in the lamina propria (3) and from neutrophils and macrophages containing TNF-α passing into the lumen and releasing their cytoplasmic cytokine on lysis (1).

The role of cytokines in the pathogenesis of enteric infections is still not known. On the basis of observations in inflammatory bowel disease and of the findings of nondetectable proinflammatory cytokine concentrations in stools in pathogen-negative diarrhea and in stools without diarrhea (2), we hypothesized that detectable TNF-α and interleukin-6 (IL-6) concentrations in stool may simply reflect their involvement in the pathogenesis of gastroenteritis and may provide a simple way to differentiate the type of gastroenteritis in children when microbiologic diagnosis is impossible or delayed.