Rosen & Barkin's 5-Minute Emergency Medicine Consult (211 page)

Bowel movements characterized as frequent (>3/day), loose, and watery owing to an infectious or toxin exposure

• Viruses:
  
  • 50–70% of all cases
    
• Invasive bacteria:
  
  • Campylobacter
    :
    
    • Contaminated food or water, wilderness water, birds, and animals
      
    • Most common bacterial diarrhea
      
    • Gross or occult blood is found in 60–90%.
      
  • Salmonella:
    
    • Contaminated water, eggs, poultry, or dairy products
      
    • Typhoid fever (
      Salmonella typhi
      ) characterized by unremitting fever, abdominal pain, rose spots, splenomegaly, and bradycardia
      
  • Shigella:
    
    • Fecal or oral route
      
  • Vibrio parahaemolyticus:
    
    • Raw and undercooked seafood
      
  • Yersinia:
    
    • Contaminated food (pork), water, and milk
      
    • May present as mesenteric adenitis or mimic appendicitis
      
• Bacterial toxin:
  
  • Escherichia coli
    :
    
    • Major cause of traveler’s diarrhea
      
    • Ingestion of food or water contaminated by feces
      
  • Staphylococcus aureus:
    
    • Most common toxin-related disease
      
    • Symptoms 1–6 hr after ingesting food
      
  • Bacillus cereus:
    
    • Classic source—fried rice left on steam tables
      
    • Symptoms within 1–36 hr
      
  • Clostridium difficile:
    
    • Antibiotic-associated enteritis linked to pseudomembranous colitis
      
    • Incubation period within 10 days of exposure or initiation of antibiotics
      
  • Aeromonas hydrophila:
    
    • Aquatic sources primarily
      
    • Affects children <3 yr of age
      
    • Fecal leukocytes absent
      
  • Cholera:
    
    • Caused by enterotoxin produced by
      Vibrio cholerae
      
    • Profuse watery stools with mucus (classic appearance of rice-water stools)
      
• Protozoa:
  
  • Giardia lamblia
    :
    
    • Most common cause of parasite gastroenteritis in North America
      
    • High-risk groups: Travelers, children in day care centers, institutionalized people, homosexual men, and campers who drink untreated mountain water
      
  • Cryptosporidium parvum
    :
    
    • Commonly carried in patients with AIDS
      
  • Entamoeba histolytica
    (entamebiasis):
    
    • 5–10% extraintestinal manifestations (hepatic amebic abscess)
      

• Most are viral in origin and self-limited.
  
• Rotavirus accounts for 50%.
  
• Shigella
  : Infections associated with seizures
  
• Focus evaluation on state of hydration.
  

DIAGNOSIS

• Loose, watery bowel movements
  
• Bloody stools with mucus
  
• Abdominal pain and cramps, tenesmus, flatulence
  
• Fever, headache, myalgias
  
• Nausea, vomiting
  
• Dehydration, lethargy, and stupor
  

• Dry mucous membranes
  
• Abdominal tenderness
  
• Perianal inflammation, fissure, fistula
  

• Digital rectal exam to determine presence of gross or occult blood
  
• Fecal leukocyte determination:
  
  • Present with invasive bacteria
    
  • Absent in protozoal infections, viral, toxin-induced food poisoning
    

• CBC—indications:
  
  • Significant blood loss
    
  • Systemic toxicity
    
• Electrolytes, glucose, BUN, creatinine—indications:
  
  • Lethargy, significant dehydration, toxicity, or altered mental status
    
  • Diuretic use, persistent diarrhea, chronic liver, or renal disease
    
• Stool culture—indications:
  
  • Presence of fecal leukocytes
    
  • Historical markers: Immunocompromised, travel, homosexual
    
  • Public health: Food handler, day care or health care worker, institutionalized
    
• Blood cultures—indications:
  
  • Suspected bacteremia or systemic infections
    
  • Ill patients requiring admission
    
  • Immunocompromised
    
  • Elderly patients and infants
    

Abdominal radiographs:

• No value unless obstruction or toxic megacolon suspected
  

• Ulcerative colitis
  
• Crohn's disease
  
• Mesenteric ischemia
  
• Diverticulitis, anal fissures, hemorrhoids
  
• Irritable bowel syndrome
  
• Milk and food allergies
  
• Malrotation with midgut volvulus
  
• Meckel diverticulum
  
• Intussusception
  
• Appendicitis
  
• Drugs and toxins:
  
  • Mannitol
    
  • Sorbitol
    
  • Phenolphthalein
    
  • Magnesium-containing antacids
    
  • Quinidine
    
  • Colchicine
    
  • Mushrooms
    
  • Mercury poisoning
    

TREATMENT

• Difficult IV access with severe dehydration
  
• Avoid exposure to contaminated clothes or body substances.
  

• ABCs
  
• IV fluid with 0.9% normal saline (NS) resuscitation for severely dehydrated
  

• Oral fluids for mild dehydration (Gatorade/Pedialyte)
  
• IV fluids for:
  
  • Hypotension, nausea and vomiting, obtundation, metabolic acidosis, significant hypernatremia or hyponatremia
    
  • 0.9% NS bolus: 500 mL–1 L (peds: 20 mL/kg) for resuscitation, then 0.9% NS or D
    ₅
    W 0.45% NS (peds: D
    ₅
    W 0.25% NS) to maintain adequate urine output
    
• Bismuth subsalicylate (Pepto-Bismol):
  
  • Antisecretory agent
    
  • Effective clinical relief without adverse effects
    
• Kaolin-pectin (Kaopectate):
  
  • Reduces fluidity of stools
    
  • Does not influence course of disease
    
• Antimotility drugs: Diphenoxylate (Lomotil), loperamide (Imodium), paregoric, codeine:
  
  • Appropriate in noninfectious diarrhea
    
  • Initial use of sparse amounts to control symptoms in infectious diarrhea
    
  • Avoid prolonged use in infectious diarrhea—may increase duration of fever, diarrhea, and bacteremia and may precipitate toxic megacolon
    
• Antibiotics for infectious pathogens:
  
  • Campylobacter:
    Quinolone or erythromycin
    
  • Salmonella:
    Quinolone or trimethoprim–sulfamethoxazole (TMP-SMX)
    
  • Typhoid fever:
    Ceftriaxone
    
  • Shigella:
    Quinolone, TMP-SMX, or ampicillin
    
  • V. parahaemolyticus:
    Tetracycline or doxycycline
    
  • C. difficile:
    Metronidazole or vancomycin
    
  • E. coli:
    Quinolone or TMP-SMX
    
  • G. lamblia:
    Metronidazole or quinacrine
    
  • E. histolytica
    (entamebiasis): Iodoquinol or metronidazole
    

• Ampicillin: 500 mg (peds: 20 mg/kg/24h) PO or IV q6h
  
• TMP-SMX (Bactrim DS): 1 tab (peds: 8–10 mg TMP/40–50 mg SMX/kg/24h) PO or 4–5 mg/kg TMP IV BID
  
• Ceftriaxone: 1 g (peds: 50–75 mg/kg/12h) IM or IV q12h.
  
• Ciprofloxacin (quinolone): 500 mg PO or 400 mg IV q12h (>18 yr)
  
• Doxycycline: 100 mg PO or 100 mg IV q12h
  
• Erythromycin: 500 mg (peds: 40–50 mg/kg/24h) PO QID
  
• Iodoquinol: 650 mg (peds: 30–40 mg/kg/24h not to exceed 2 g daily) PO TID
  
• Metronidazole: 250 mg (peds: 35 mg/kg/24h) PO TID (>8 yr)
  
• Quinacrine: 100 mg (peds: 6 mg/kg/24h) PO TID
  
• Tetracycline: 500 mg PO or IV q6h
  
• Vancomycin: 125–500 mg (peds: 40 mg/kg/24h) PO q6h
  

FOLLOW-UP

• Hypotension, unresponsive to IV fluids
  
• Significant bleeding
  
• Signs of sepsis or toxicity
  
• Intractable vomiting or abdominal pain
  
• Severe electrolyte imbalance or metabolic acidosis
  
• Altered mental status
  
• Children with >10–15% dehydration
  

• Mild cases requiring oral hydration
  
• Dehydration responsive to IV fluids
  

Cases of prolonged diarrhea may be referred to a gastroenterologist for further workup.

Since diarrhea is self-limiting, follow-up is optional.

• Avoid prolonged use of antimotility drugs in infectious diarrhea.
  
• TMP-SMX (Bactrim DS), ciprofloxacin, doxycycline, and tetracycline are contraindicated in pregnancy. Metronidazole may be used in the 3rd trimester.
  
• Health care providers and food handlers with documented infectious diarrhea may need clearance to return to work from their local health department.
  
• Infectious diarrhea with
  C. difficile
  is on the rise, especially in nursing home patients.
  

• Denno DM, Shaikh N, Stapp JR, et al. Diarrhea etiology in a pediatric emergency department: A case control study.
  Clin Infect Dis
  . 2012;55:897–904.
  
• DuPont HL. Clinical practice. Bacterial diarrhea.
  N Engl J Med.
  2009;361(16):1560–1569.
  
• Leffler DA, Lamont JT. Treatment of Clostridium difficile–associated disease.
  Gastroenterology
  . 2009;136:1899–1912.
  
• Mehal JM, Esposito DH, Holman RC, et al. Risk factors for diarrhea-associated infant mortality in the United States, 2005–2007.
  Pediatr Infect Dis J
  . 2012;31:717–721.