Two patients with primary pneumatosis cystoides intestinalis are prese
nted. In both cases, the sigmoid colon was involved and there were no
major complications. On computed tomography (CT), at lung window setti
ngs, the gas cysts in the colonic wall were clearly delineated. CT was
useful in confirming the intramural gas cysts in patients with primar
y pneumatosis cystoides intestinalis.