> Table of Contents > Diarrhea, Acute
Diarrhea, Acute
Pia Prakash, MD
Bedoor Alabbas, MD
Marie L. Borum, MD, EdD, MPH
image BASICS
  • Acute diarrhea is an abnormal increase in stool water content, volume, or frequency (≥3 in 24 hours) for <14 days duration.
  • Acute viral diarrhea (50-70%)
    • Most common; usually occurs for 1 to 3 days and is typically self-limited
  • Bacterial diarrhea (15-20%)
    • Develops 6 to 24 hours after ingestion of contaminated food
    • Suspect when concurrent illness in others who have shared potentially contaminated food
    • Suspect Clostridium difficile in patients with recent antibiotic use or hospitalization.
  • Protozoal infections (10-15%)
    • Prolonged, watery diarrhea in areas with contaminated water supply
    • Consider if diarrhea lasts >7 days.
  • Traveler's diarrhea typically begins 3 to 7 days after arrival in foreign location; rapid onset
  • In developing countries, acute diarrhea is more common in children. No age predilection in developed countries
  • Acute diarrhea accounts for >128,000 U.S. hospital admissions and approximately 1.5 million worldwide deaths annually (1).
  • 7th leading cause of death worldwide (1)
  • Affects 11% of the general population
  • In developing countries, acute diarrhea is most common in children aged >5 years.
  • Rotavirus and adenovirus common in children >2 years
  • In developing world, acute diarrhea is largely due to contaminated food and water.
  • Bacterial
    • Escherichia coli
    • Salmonella
    • Shigella
    • Campylobacter jejuni
    • Vibrio parahaemolyticus
    • Vibrio cholerae
    • Yersinia enterocolitica
    • C. difficile
    • Staphylococcus aureus
    • Bacillus cereus
    • Clostridium perfringens
    • Listeria monocytogenes
  • Viral
    • Rotavirus and norovirus (most common)
    • Adenovirus
    • Astrovirus
    • Cytomegalovirus (in immunocompromised)
  • Protozoal
    • Giardia lamblia
    • Entamoeba histolytica
    • Cryptosporidium
    • Isospora belli
    • Cyclospora
    • Microspora
  • Pathophysiology (2)
    • Noninflammatory: increased intestinal secretions without disruption of intestinal mucosa
    • Inflammatory: disrupts intestinal mucosal integrity, with subsequent tissue invasion/damage
  • Viral diarrhea: changes in small intestine cell morphology that include villous shortening, increased number of crypt cells, and increased cellularity of the lamina propria
  • Bacterial diarrhea: Bacterial invasion of colonic wall leads to mucosal hyperemia, edema, and leukocytic infiltration.
  • Travel to developing countries
  • Failure to observe food/water precautions
  • Immunocompromised host
  • Antibiotic use
  • Proton pump inhibitor (PPI) use (3)
  • Daycare attendance
  • Nursing home residence
  • Pregnancy (12-fold increase for listeriosis) (2)
  • Frequent hand washing
  • Proper food and water precautions, particularly during foreign travel—“boil it, peel it, cook it, or forget it”
  • Avoid undercooked meats, raw fish, unpasteurized milk.
  • Rotavirus vaccine (for infants) (4)
  • Typhoid fever and cholera vaccine (for travel to endemic areas) (5,6)
  • Probiotics have not been shown to prevent traveler's diarrhea (7).
  • Inflammatory bowel disease
  • Immunocompromise (HIV, malignancy, chemotherapy)
  • General: fever, volume status—pulse; blood pressure
  • Cardiovascular: tachycardia, orthostatic hypotension
  • Abdominal: bowel sounds, abdominal distention, abdominal tenderness, masses, hepatomegaly
  • Rectal: stool with blood or mucus, tenderness
  • Skin: turgor and capillary refill
Geriatric Considerations
Watery diarrhea with chronic constipation may be caused by fecal impaction or obstructing neoplasm.
  • Inflammatory bowel disease
  • Malabsorption
  • Medications (cholinergic agents, magnesium-containing antacids, chemotherapy, antibiotics)
  • C. difficile colitis secondary to antibiotic use
  • Diverticulitis; ischemic colitis
  • Spastic (irritable) colon
  • Fecal impaction
  • Endocrinopathies: thyroid disease
  • Neoplasia
Initial Tests (lab, imaging)
  • CBC
    • Leukocytosis, anemia from blood loss, eosinophilia (parasite infection)
  • Serum electrolytes
  • BUN and creatinine may elevate with volume depletion.
  • Nonanion gap metabolic acidosis
  • Stool sample
    • Occult blood present in inflammatory bowel disease, bowel ischemia, and certain bacterial infections
    • Fecal leukocytes
    • Stool ova and parasites
    • Stool culture
      • For bloody diarrhea, consider Salmonella, Shigella, Campylobacter, E. coli 0157:H7, Y. enterocolitica, E. histolytica.
    • C. difficile toxin (especially with recent hospitalization or antibiotic use) (8)[B]
    • Giardia ELISA >90% sensitive in at-risk population
    • Abdominal radiographs (flat plate and upright) if severe abdominal pain or concern for obstruction
    • Abdominal CT scan is preferred to evaluate intraabdominal and intestinal disease.
Diagnostic Procedures/Other
  • Consider sigmoidoscopy or colonoscopy in patients with persistent diarrhea, when there is no clear diagnosis after routine blood and stool tests, and if empiric or supportive therapy is ineffective.
  • Consider colonoscopy in immunocompromised patients to evaluate for CMV colitis.
  • Colonoscopy helps to distinguish infectious diarrhea from inflammatory bowel disease.

  • Oral rehydration and electrolyte management are key elements in successful treatment (9)[A].
  • Diet, as tolerated—“if the gut works, use it”
  • IV fluids if patient cannot tolerate oral rehydration or presents with severe dehydration
First Line
  • Consider empiric antibiotics (fluoroquinolones or macrolides) in patients with signs and symptoms of systemic infection and severe cases of traveler's diarrhea (10).
    • Fever
    • Bloody diarrhea
    • Presence of fecal leukocytes
    • Immunocompromised host
    • Signs of volume depletion
    • Symptoms >1 week
  • Tailor antibiotics to stool culture results (11)
    • Giardia: metronidazole, tinidazole
    • E. histolytica: metronidazole
    • Shigella: ciprofloxacin or azithromycin
    • Campylobacter: azithromycin or erythromycin
    • C. difficile: metronidazole, PO vancomycin, or fidaxomicin
    • Traveler's diarrhea: patients without fever or dysentery: rifaximin 200 mg PO TID or ciprofloxacin 500 mg PO BID. Patients with fever or dysentery: azithromycin 500 mg PO × 1 on day 1 followed by 250 mg PO for 4 days
  • General considerations
    • Antibiotics are not recommended in Salmonella infections unless caused by Salmonella typhosa, or if the patient is febrile or immunocompromised.
    • Avoid antibiotics in patients with E. coli 0157:H7 due to risk for hemolytic-uremic syndrome.
    • Antibiotics are not indicated for foodborne toxigenic diarrhea.
    • Avoid antimotility agents (e.g., loperamide) when possible in patients suspected of having infectious diarrhea (especially, E. coli 0157:H7) or antibiotic-associated colitis.
    • Antimotility agents, when used in combination with antibiotics, may speed recovery from traveler's diarrhea (12)[A].
  • Significant medication interactions
    • Salicylate absorption from bismuth subsalicylate can cause toxicity in patients already taking aspirin-containing compounds and may alter anticoagulation control in patients taking warfarin.
    • Avoid alcoholic beverages with metronidazole due to the possibility of a disulfiram reaction.
  • Probiotic use above 1010/g may help in patients with antibiotic-associated diarrhea (3)[A].
  • The use of probiotics is controversial in the treatment of acute diarrhea. Probiotics should be avoided in immunocompromised patients (3,13)[A].
  • Probiotics shorten the duration of symptoms in pediatric (14).
  • Zinc supplementation can decrease diarrhea-related morbidity and mortality (15)[A].
Admission Criteria/Initial Stabilization
Outpatient management, except for patients who are severely ill with signs of volume depletion
  • Early refeeding is encouraged. Regular diets are as effective as restricted diets.
  • The traditional bananas, rice, applesauce, toast (BRAT) diet has little evidence-based support, despite heavy clinical use, and may result in suboptimal nutrition.
  • During periods of active diarrhea, coffee, alcohol, dairy products, fruits, vegetables, red meats, and heavily seasoned foods may exacerbate symptoms.
See guidelines in “General Prevention” section.
Acute diarrhea is rarely life-threatening if adequate hydration is maintained.
1. World Health Organization. The top 10 causes of death in the world, 2000 and 2012 fact sheet. http://www.who.int/mediacentre/factsheets/fs310/en/
2. Barr W, Smith A. Acute diarrhea. Am Fam Physician. 2014;89(3):180-189.
3. Janarthanan S, Ditah I, Adler DG, et al. Clostridium difficile-associated diarrhea and proton pump inhibitor therapy: a meta-analysis. Am J Gastroenterol. 2012;107(7):1001-1010.
4. Soares-Weiser K, Maclehose H, Bergman H, et al. Vaccines for preventing rotavirus diarrhoea: vaccines in use. Cochrane Database Syst Rev. 2012;(11):CD008521.
5. Anwar E, Goldberg E, Fraser A, et al. Vaccines for preventing typhoid fever. Cochrane Database Syst Rev. 2014;(1):CD001261.
6. Sinclair D, Abba K, Zaman K, et al. Oral vaccines for preventing cholera. Cochrane Database Syst Rev. 2011;(3):CD008603.
7. Ritchie ML, Romanuk TN. A meta-analysis of probiotic efficacy for gastrointestinal diseases. PLoS One. 2012;7(4):e34938.
8. Pawlowski SW, Warren CA, Guerrant R. Diagnosis and treatment of acute or persistent diarrhea. Gastroenterology. 2009;136(6):1874-1886.
9. DuPont HL. Clinical practice. Bacterial diarrhea. N Engl J Med. 2009;361(16):1560-1569.
10. Dryden MS, Gabb RJ, Wright SK. Empirical treatment of severe acute community-acquired gastroenteritis with ciprofloxacin. Clin Infect Dis. 1996;22(6):1019-1025.
11. DuPont HL. Acute infectious diarrhea in immunocompetent adults. N Engl J Med. 2014;370(16):1532-1540.
12. Riddle MS, Arnold S, Tribble DR. Effect of adjunctive loperamide in combination with antibiotics on treatment outcomes in traveler's diarrhea: a systematic review and meta-analysis. Clin Infect Dis. 2008;47(8):1007-1014.
13. Goldenberg JZ, Ma SS, Saxton JD, et al. Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children. Cochrane Database Syst Rev. 2013;(5):CD006095.
14. Corrêa NB, Penna FJ, Lima FM, et al. Treatment of acute diarrhea with Saccharomyces boulardii in infants. J Pediatr Gastroenterol Nutr. 2011;53(5): 497-501.
15. Walker CL, Black RE. Zinc for the treatment of diarrhoea: effect on diarrhoea morbidity, mortality and incidence of future episodes. Int J Epidemiol. 2010;39(Suppl 1):i63-i69.
16. Schwille-Kiuntke J, Mazurak N, Enck P. Systematic review with meta-analysis: post-infectious irritable bowel syndrome after travellers' diarrhoea. Aliment Pharmacol Ther. 2015;41(11):1029-1037.
Additional Reading
  • Chen CC, Kong MS, Lai MW, et al. Probiotics have clinical, microbiologic, and immunologic efficacy in acute infectious diarrhea. Pediatr Infect Dis J. 2010;29(2):135-138.
  • DuPont HL. Systematic review: the epidemiology and clinical features of travellers' diarrhoea. Aliment Pharmacol Ther. 2009;30(3):187-196.
  • Johnston BC, Ma SS, Goldenberg JZ, et al. Probiotics for the prevention of Clostridium difficile-associated diarrhea: a systematic review and meta-analysis. Ann Intern Med. 2012;157(12):878-888.
  • Koo HL, DuPont HL. Rifaximin: a unique gastrointestinal-selective antibiotic for enteric diseases. Curr Opin Gastroenterol. 2010;26(1):17-25.
  • McFarland LV. Evidence-based review of probiotics for antibiotic-associated diarrhea and Clostridium difficile infections. Anaerobe. 2009;15(6):274-280.
See Also
Botulism; Cholera; Food Poisoning, Bacterial
  • R19.7 Diarrhea, unspecified
  • A09 Infectious gastroenteritis and colitis, unspecified
  • A08.4 Viral intestinal infection, unspecified
Clinical Pearls
  • Viruses are the most common causes of acute diarrheal illness in the United States.
  • Oral rehydration is the most important step in treating acute diarrhea.
  • Routine stool culture is not recommended, unless the patient presents with bloody diarrhea, fever >38.5°C, severe dehydration, signs of inflammatory disease, persistent symptoms >3 to 7 days, or immunosuppression.
  • Start empiric antibiotics in patients who are severely ill or immunocompromised.