Diarrhea, Nausea, or Vomiting

Symptomatic therapy
Oral rehydration therapy

Continue symptomatic therapy; further evaluation if no resolution

Culture for: Shigella, Salmonella, C. jejuni
Consider: C.difficile cytotoxin

Specific antiparasitic therapy

Consider: Empirical antimicrobial therapy

End

Resolution

Continued illness

^1.   Diarrhea lasting >2 weeks is generally defined as chronic; in such cases, many of the causes of acute diarrhea are much less likely, and a new spectrum of causes needs to be considered.

^2.   Fever often implies invasive disease, although fever and diarrhea may also result from infection outside the gastrointestinal tract, as in malaria.

^3.   Stools that contain blood or mucus indicate ulceration of the large bowel. Bloody stools without fecal leukocytes should alert the laboratory to the possibility of infection with Shiga toxin-producing enterohemorrhagic Escherichia coli. Bulky white stools suggest a small-intestinal process that is causing malabsorption. Profuse “rice-water” stools suggest cholera or a similar toxigenic process.

^4.   Frequent stools over a given period can provide the first warning of impending dehydration.

^5.   Abdominal pain may be most severe in inflammatory processes like those due to Shigella, Campylobacter, and necrotizing toxins. Painful abdominal muscle cramps, caused by electrolyte loss, can develop in severe cases of cholera. Bloating is common in giardiasis. An appendicitislike syndrome should prompt a culture for Yersinia enterocolitica with cold enrichment.

^6.   Tenesmus (painful rectal spasms with a strong urge to defecate but little passage of stool) may be a feature of cases with proctitis, as in shigellosis or amebiasis.

^7.   Vomiting implies an acute infection (e.g., a toxin-mediated illness or food poisoning) but can also be prominent in a variety of systemic illnesses (e.g., malaria) and in intestinal obstruction.

^8.   Asking pts whether anyone else they know is sick is a more efficient means of identifying a common source than is constructing a list of recently eaten foods. If a common source seems likely, specific foods can be investigated. See text for a discussion of bacterial food poisoning.

^9.   Current antibiotic therapy or a recent history of treatment suggests Clostridium difficile diarrhea. Stop antibiotic treatment if possible and consider tests for C. difficile toxins. Antibiotic use may increase the risk of chronic intestinal carriage following salmonellosis.

End

Assess:
  Duration (>1 day)
  Severity

Yes

No

Obtain history:

  Duration¹ 
  Fever² 
  Appearance of stool ³ 
  Frequency of bowel movements⁴ 
  Abdominal pain ⁵ 
  Tenesmus ⁶ 
  Vomiting ⁷ 
  Common source ⁸ 
  Antibiotic use ⁹ 
  Travel
  and
  Obtain stool to be examined for WBCs (and, if >10 days, for parasites)

Noninflammatory (no WBCs; see Table 85-1)

Inflammatory (WBCs)

Examine stool for parasites