Internal Medicine

0521779407-10 CUNY1086/Karliner 0 521 77940 7 June 7, 2007 18:40

Infectious Diarrheas 825

Infectious Diarrheas..................................

SUZANNE M. MATSUI, MD and JEFFREY W. KWAN, MD, MS

history & physical

History

■most episodes self-limiting (nearly half last <1 day); evaluate those

with more severe illness

■character of fecal output: >6 unformed stools/24 h, blood or mucus

in stools

■presence of fever, vomiting, dysentery, abdominal pain, tenesmus

■duration of illness (>48 h)

■male homosexual

■history of immunocompromise

■setting in which patient became ill: travel, institutional/day care/

family exposure, recent antibiotic use

■age of patient

■comorbid conditions: vascular disease, IBD, radiation therapy

Signs and Symptoms

■noninflammatory (less likely to require extensive evaluation):

➣profuse watery diarrhea may precipitate dehydration

➣minimal or no fever

■inflammatory (usually associated with specific pathogen and treat-

ment):

➣dysentery

➣many small-volume stools with blood and mucus

➣fever >38.5◦C (101.3◦F) suggests invasive pathogen/inflamma-

tion

■enteric fever

➣constipation early in course: S. typhi, C. fetus, some Yersinia

➣systemic infection

➣infection returns to gut via biliary tract

tests

■moderate to severe acute infectious diarrhea: screen with fecal leuko-

cytes or lactoferrin (leukocyte marker) or fecal occult blood

■severe diarrhea: stool culture; O & P, if parasitic/protozoal infec-

tion suspected (>10 d duration, consumption of untreated water,

homosexual/AIDS patients); C. difficile toxins A & B, if suspected;

endoscopy (to distinguish between IBD and infectious diarrhea, to