||Profuse and chronic watery diarrhea typically associated with urgency and incontinence that begins acutely and lasts from 2-36 months.
||An estimated 5,000-8,000 patients with chronic diarrhea clinically similar to Brainerd diarrhea are cared for by U.S. gastroenterologists each year. Approximately every 3 years, CDC investigates an outbreak of Brainerd diarrhea affecting 50-100 people.
||No known sequelae; however, many people suffer adverse psychologic consequences related to the long duration of an incapacitating illness.
||Untreated water has been implicated in several outbreaks and unpasteurized cow's milk has been implicated in one.
||The elderly appear to be at greatest risk for Brainerd diarrhea, although several cases among children and young adults have been described.
||No surveillance system exists for Brainerd diarrhea or for other chronic diarrheal syndromes of unknown etiology (e.g., collagenous colitis, microscopic colitis).
||Data are insufficient to indicate an increase or decrease in incidence.
||Despite numerous intensive laboratory investigations, the etiologic agent of Brainerd diarrhea remains a mystery. Histologic criteria for distinguishing Brainerd diarrhea from other chronic diarrheal syndromes were developed from outbreak-related specimens, but need to be evaluated in specimens from patients with sporadic cases of chronic idiopathic secretory diarrhea.
||Newer techniques, such as ribosomal RNA amplification on sterile site tissue biopsies may shed new light on the etiologic agent. The histologic criteria can be tested against specimens from a recent outbreak.