Three adult cases of intussusceptions, associated with enteroviruses occurring within a 3-week period, are reported. Virological studies include viral RNA detection in stool samples and staining for enterovirus protein by immunoperoxidase staining of the resected intestinal tissues. A new mechanism for intussusception associated with enterovirus is proposed. Tap water was implicated in the outbreak. Better monitoring of drinking-water may prevent other cases of non-polio enterovirus infection.