Diarrhea, Adult, Emergency Medicine

Basics

Description

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

Etiology

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 travelers 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

Signs and Symptoms

History

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

Physical Exam

Dry mucous membranes
Abdominal tenderness
Perianal inflammation, fissure, fistula

Essential Workup

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

Diagnosis Tests & Interpretation

Lab

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

Imaging
Abdominal radiographs:

No value unless obstruction or toxic megacolon suspected

Differential Diagnosis

Ulcerative colitis
Crohns 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

Pre-Hospital

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

Initial Stabilization/Therapy

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

Ed Treatment/Procedures

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 D5W 0.45% NS (peds: D5W 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

Medication

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

Disposition

Admission Criteria

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

Discharge Criteria

Mild cases requiring oral hydration
Dehydration responsive to IV fluids

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

Followup Recommendations

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

Pearls and Pitfalls

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.

Additional Reading

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.

Codes

ICD9

008.5 Bacterial enteritis, unspecified
008.8 Intestinal infection due to other organism, not elsewhere classified
787.91 Diarrhea
008.43 Intestinal infection due to campylobacter
003.0 Salmonella gastroenteritis
004.9 Shigellosis, unspecified
008.00 Intestinal infection due to E. coli, unspecified

ICD10

A04.9 Bacterial intestinal infection, unspecified
A08.4 Viral intestinal infection, unspecified
R19.7 Diarrhea, unspecified
A04.5 Campylobacter enteritis
A02.0 Salmonella enteritis
A03.9 Shigellosis, unspecified
A04.4 Other intestinal Escherichia coli infections

SNOMED

62315008 Diarrhea (finding)
111843007 Viral gastroenteritis (disorder)
274080003 Bacterial gastroenteritis (disorder)
18081009 enteric campylobacteriosis (disorder)
111817006 Infection by Shigella (disorder)
111839008 Intestinal infection due to E. coli (disorder)
302229004 Salmonella food poisoning
42338000 Salmonella gastroenteritis (disorder)

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