Diarrhea - Acute

Diarrhea is defined as an increase in the volume of bowel movements. Acute diarrhea is designated as being of less than 4 weeks’ duration. Many patients describe increased frequency or decreased consistency of bowel movements as diarrhea, so the clinician should be certain to identify whether the patient indeed suffers from diarrhea.

Differential Diagnosis

• Infectious etiologies
  –Acute (viral) gastroenteritis
  –“Traveler's diarrhea”: Shigella, Salmonella, enterotoxigenic E. coli, Campylobacter
  –Rotavirus
  –Norwalk virus
  –Yersinia enterocolitica
  –Clostridium difficile (pseudomembranous enterocolitis): Follows antibiotic use
  –Giardiasis: Foul-smelling, explosive diarrhea
  –Enterovirus
• Lactose intolerance
• IBS: Alternating diarrhea and constipation
• Ischemic colitis: Associated with history of atherosclerotic disease (CAD, PVD, AAA)
• Inflammatory bowel disease (ulcerative colitis, Crohn's disease)
• Medications (e.g., laxatives, antibiotics, anticholinergics, chemotherapy, metformin)
• Malabsorption syndromes
• Vasculitis
• Neoplasia
• Appendicitis
• Adrenal insufficiency
• Hyperthyroidism
• HIV
• Less common etiologies include E. coli O157:H7 (commonly associated with raw meat; invasive, bloody diarrhea), Cryptosporidium, Cyclospora, Isospora belli, typhoid fever

Workup and Diagnosis

• History and physical examination
  –Proper history should include travel history, woodland exposure (Giardia), immune status, and sick contacts
  –Blood pressure and pulses, including orthostatics
  –Full abdominal examination
  –Back, genital, and rectal examinations
  –Skin examination (e.g., jaundice, turgor)
  –Signs of dehydration (e.g., loss of jugular pulsations, dry mucous membranes, skin tenting, orthostasis)

• Stool examination and culture are usually indicated
  –Fecal leukocytes suggest for infectious causes
  –Fecal lactoferrin suggests laxative abuse
  –Ova and parasites (for Giardia and Cryptosporidium) should be considered in at-risk patients with persistent diarrhea
  –Stool cultures may identify Salmonella, Shigella, Campylobacter, Yersinia, or E. Coli
  –Test stool for C. difficile toxin, if suspected
  –Stool osmolar gap is elevated in osmotic and malabsorptive diarrhea and decreased in infectious/secretory diarrhea

• Initial laboratory studies may include CBC, electrolytes, BUN/creatinine, glucose, urinalysis, liver function tests, and hepatitis serologies
• Therapeutic trial of a lactose-free diet or lactose intolerance testing may be useful
• Barium enema, colonoscopy, and/or flexible sigmoidoscopy may be indicated
• Consider HIV testing

Treatment

• Treatment is generally supportive
• Fluid resuscitation (oral, if possible, or IV)
• Antimotility agents: Opiates (e.g., loperamide) and parasympathetic inhibitors (e.g., diphenoxylate plus atropine); former concerns that these agents may slow the clearance of pathogens have been disproved
• Antibiotic therapy is reserved for severe disease
  –Most authorities recommend empiric treatment with a fluoroquinolone or trimethoprin-sulfamethoxasole in patients with severe or bloody diarrhea, fever, or fecal leukocytes
  –If Giardia, C. difficile, or E. histolytica is suspected, treat empirically with metronidazole
  –Antibiotic therapy increases the risk of hemolytic-uremic syndrome in children with E. coli O157:H7
  –There is no good evidence that antibiotics prolong the carrier state in Salmonella infections
• Advise patient to hydrate with glucose-containing, caffeine-free beverages, and to avoid lactose, sorbitol-containing gum, and raw fruit until symptoms subside

Book Source Details

• Book Title: In a Page: Signs and Symptoms
• Author(s): Scott Kahan, Ellen G. Smith
• Year of Publication: 2004
• Copyright Details: In a Page: Signs and Symptoms, Copyright © 2004 Lippincott Williams & Wilkins.

Other Book Chapters Related to Diarrhea

Read excerpts from these other book chapters related to Diarrhea:

Copyright Details: In a Page: Signs and Symptoms, Copyright © 2008 Williams & Wilkins.

More About Causes of Diarrhea

• Back to symptom: Diarrhea: Introduction (review 2132 causes)
• Next Book Extract About Diarrhea: Diarrhea - Chronic (In a Page: Signs and Symptoms)
• All Book Extracts: All Online Book Extracts for Diarrhea

More About This Book: Title: In a Page: Signs and Symptoms Authors: Scott Kahan, Ellen G. Smith Publisher: Lippincott Williams & Wilkins Copyright: 2004 ISBN: 1-4051-0368-X