This review provides a practical, simple, and logical approach to the diagn
osis and management of patients with acute infectious diarrhea, one of the
most common diagnoses in clinical practice. Diarrhea in the immunocompromis
ed host, traveler's diarrhea, and diarrhea in the hospitalized patient are
also discussed. Most episodes of acute diarrhea are self-limited, and inves
tigations should be performed only if the results will influence management
and outcome. After an adequate history and physical examination, the clini
cian should be able to classify the acute diarrheal illness, assess the sev
erity, and determine whether investigations are needed. Most patients do no
t require specific therapy. Therapy should mainly be directed at preventing
dehydration. Various home remedies frequently suffice in mild, self-limite
d diarrhea. However, in large-volume, dehydrating diarrhea, oral rehydratio
n solutions should be used, as they are formulated to stimulate sodium and
water absorption. Antidiarrheal agents can be useful in reducing the number
of bowel movements and diminishing the magnitude of fluid loss. The most u
seful agents are opiate derivatives and bismuth subsalicylate. Antibiotic t
herapy is not required in most patients with acute diarrheal disorders. Gui
delines for their use are presented. Am J Med. 1999;106:670-676. (C) 1999 b
y Excerpta Medica, Inc.