Acute Diarrhea

Aka: Acute Diarrhea, Diarrhea, Acute Infectious Diarrhea, Infectious Diarrhea, Bacterial Diarrhea, Acute Inflammatory Diarrhea, Dysentery, Infectious Colitis

1. See Also
   1. Gastroenteritis
   2. Pediatric Diarrhea
   3. Chronic Diarrhea
   4. Infectious Diarrhea Causes
   5. Traveler's Diarrhea Management
   6. Traveler's Diarrhea Prophylaxis
   7. Traveler's Diarrhea Prevention
   8. Waterborne Illness
   9. Foodborne Illness
   10. Medication-Induced Diarrhea
   11. Diarrhea Management in Children
   12. Management of Moderate Diarrhea under age 2 years
   13. Management of Mild Diarrhea under age 2 years
   14. Pediatric Diarrhea Fluid Replacement
   15. Oral Rehydration Solution
   16. Diarrhea in HIV
2. Definition
   1. Gastroenteritis
      1. Inflammation of the Gastrointestinal Tract (Stomache and Small Intestine)
      2. Typical presentation is Vomiting followed by Diarrhea
      3. Most typically secondary to Viral Gastroenteritis
         1. Can also be caused by Bacteria with ingestion of preformed toxin
   2. Diarrhea
      1. Frequent liquid stools
         1. Adults: >200 g/day of stool (at least 3 Bowel Movements daily)
         2. Children: >20 g/kg/day of stool
      2. Timing
         1. Acute Diarrhea: Duration <2 weeks
         2. Chronic Diarrhea: Duration >4 weeks
            1. Chronic Fatty Diarrhea
            2. Chronic Inflammatory Diarrhea
            3. Chronic Watery Diarrhea
3. Epidemiology
   1. Foodbourne Diarrhea cases: 48 million/year U.S.
   2. Hospitalizations: 128,000/year U.S
   3. Deaths: 3000/year U.S. (2.5 Million/year worldwide)
4. Pathophysiology
   1. Small Intestine secretes and reabsorbs 10 liters/day
      1. Extrusion of Chloride from villus crypt cell (cAMP)
      2. Absorption at villus tip
   2. Diarrhea classified as:
      1. Watery Diarrhea
         1. Secretory Diarrhea
            1. Stool Sodium high (60-120 meq/L)
            2. Hypersecretion by intestinal crypts
         2. Osmotic Diarrhea (osmotic loss of free water)
            1. Stool Sodium low (30-40 meq/L)
            2. Ingestion of non-digestable agents that draw water from the bowel wall
      2. Inflammatory Diarrhea
         1. Severe Diarrhea with pus or blood present in the stool
         2. Associated with fever, Abdominal Pain and tenesmus
      3. Fatty Diarrhea (Malabsorption)
         1. See Chronic Diarrhea
         2. Large greasy, frothy pale stools with foul odor
   3. Serum Electrolyte loss
      1. Serum Bicarbonate loss
      2. Serum Potassium loss
5. Causes: Acute Vomiting (Gastroenteritis)
   1. See Vomiting Causes
   2. See Foodborne Illness
   3. Severe Emergency Department cases in adults
      1. Norovirus (26%)
      2. Rotavirus (18%)
      3. Salmonella (5.3%)
      4. Bresee (2012) J Infect Dis 205 (9): 1374-81 [PubMed]
6. Causes: Acute Diarrhea
   1. Noninfectious Causes
      1. See Osmotic Diarrhea
      2. See Secretory Diarrhea
      3. Common Causes
         1. Intestinal Obstruction
         2. Toxic Ingestions
         3. Inflammatory Bowel Disease (and other inflammatory and Allergic Conditions)
         4. Drug Withdrawal (e.g. Opioid Withdrawal)
         5. Cholinergic Toxicity (e.g. Organophosphate Poisoning)
   2. Extra-intestinal and non-Gastroenteritis infections
      1. Diverticulitis
      2. Otitis Media
      3. Sepsis
      4. Sexually Transmitted Disease
   3. Infectious Diarrhea Causes
      1. See Infectious Diarrhea Causes
      2. See Foodborne Illness
      3. See Waterborne Illness
      4. Viruses (30-40% of episodes)
         1. Norovirus (90% of non-Bacterial diarhea)
         2. Rotavirus
      5. Bacteria and Parasites (20-30% of episodes)
         1. Inflammatory Diarrhea from Bacteria and Parasites
            1. Campylobacter jejuni (most common Bacteria)
            2. Salmonella
            3. Shigella
            4. Shiga-toxin producing E. coli (e.g. E. coli 0157:H7, Enterohemorrhagic E. coli)
               1. Causes 30% of infectious bloody Diarrhea
            5. Clostridium difficile
            6. Entamoeba histolytica
            7. Yersinia
         2. Non-Inflammatory Diarrhea from Bacteria and Parasites
            1. Enterotoxigenic E. coli
            2. Clostridium perfringens
            3. Bacillus cereus
            4. Staphylococcus aureus
            5. Giardia
            6. Cryptosporidium
            7. Vibrio Cholerae
7. Risk Factors
   1. See Chronic Diarrhea for systemic medical condition causes of Diarrhea
   2. See Infectious Diarrhea Causes
   3. Recent travel to endemic area
      1. See Traveler's Diarrhea
      2. Travel to a developing area is associated with a 25% chance of developing Diarrhea
      3. Those with Diarrhea in a developing area have an 80% chance of Bacterial Diarrhea
   4. Food associated illness
      1. See Foodborne Illness
      2. Associated with raw meats, poultry, fish, seafood, milk, rice
   5. Wilderness travel (or in developing country)
      1. See Waterborne Illness
      2. Hiking in wilderness areas (especially drinking from mountain streams)
      3. Consider Giardia, Entamoeba histolytica, Cryptospordium
   6. Day care exposure
      1. Consider Rotavirus, Cryptosporidium, Giardia, Shigella
   7. High-risk sexual behavior
      1. See Infectious Diarrhea Causes
      2. Fecal-oral sexual contact: Shigella, Salmonella, Campylobacter, Protozoa
      3. Receptive anal intercourse: Herpes Simplex Virus, Chlamydia, Gonorrhea, Syphilis
   8. Antibiotic use within 6 months or recent hospitalizations
      1. See Clostridium difficile
      2. C. Difficile Incidence in unexplained Diarrhea after 3 or more day hospitalization: 15-20%
      3. Risk of infection after antibiotics in first month (7-10 fold increased risk)
         1. Risk persists more than 3 months after antibiotics (2-3 fold increased risk)
      4. Consider Klebsiella oxytoca (uncommon)
         1. Like Clostridium difficile, causes Antibiotic-Associated Diarrhea, that may be hemorrhagic
         2. Improves after stopping antibiotics and NSAIDs
   9. Immunosuppression (e.g. HIV Infection, Chemotherapy, longterm Corticosteroids, Immunoglobulin A Deficiency)
      1. See Diarrhea in HIV
      2. Consider Cryptosporidium, Microsporida, Isospora, Cytomegalovirus
      3. Consider Mycobacterium Avium Intracellulare complex, Listeria monocytogenes
8. History: Diarrhea
   1. See Vomiting
   2. Stool size
      1. Frequent small volume stools
         1. Large Bowel
      2. Frequent large volume stools
         1. Small Bowel
   3. Stool consistency
      1. Rice-water stools (Vibrio Cholerae)
   4. Provocative agents
      1. Foods
      2. Milk
      3. Sorbitol
      4. New medications (see Medication-Induced Diarrhea)
   5. Inflammatory Diarrhea associated findings
      1. Blood or mucous present in stool
      2. Fever (typically absent in Shiga-toxin producing E. coli 0157:H7)
      3. Abdominal Pain
      4. Tenesmus (or Rectal Pain or Proctitis)
   6. Other associated findings
      1. Paresthesias (consider Neurotoxin such as Ciquatera toxin)
   7. Acute symptoms in multiple people with same food exposure (Preformed toxins)
      1. See Foodborne Illness
      2. Symptom onset within 6 hours (presents with Vomiting)
         1. Staphylococcus aureus (often from cold mayonnaise-based salads)
         2. Bacillus Cereus (meats, rice)
      3. Symptom onset within 8-16 hours (presents with Diarrhea)
         1. Clostridium perfringens (Cooked meats)
9. Symptoms
   1. Fever
      1. Campylobacter
      2. Salmonella typhi
      3. Shigella
      4. Yersinia
      5. May also occur with Clostridium difficile and Entamoeba histolytica
   2. Abdominal Pain
      1. Campylobacter
      2. Salmonella typhi
      3. Shigella
      4. Shiga-toxin producing E. coli (e.g. E. coli 0157:H7, Enterohemorrhagic E. coli)
      5. Yersinia
      6. Giardia
      7. Norovirus
      8. May also occur with Clostridium difficile and Entamoeba histolytica
   3. Nausea or Vomiting
      1. Shigella
      2. Norovirus
      3. Also occur with Campylobacter, Salmonella, E. coli 0157:H7, Yersinia, Cryptosporidium, Cyclospora, Giardia
   4. Bloody stool
      1. Shiga-toxin producing E. coli (e.g. E. coli 0157:H7, Enterohemorrhagic E. coli)
         1. Causes 30% of infectious bloody Diarrhea
      2. May also occur with Campylobacter, Clostridium difficile, Salmonella, Shigella, Yersinia
10. Exam
    1. See Vomiting
    2. Evaluate for signs of Dehydration
       1. Tachycardia
       2. Dry mucous membranes
       3. Decreased Urine Output
       4. Altered Level of Consciousness
       5. Capillary Refill
       6. Poor Skin Turgor
       7. Sunken Fontanelles (infants)
    3. Eye Exam
       1. Episcleritis
          1. Consider Inflammatory Bowel Disease such as Reiters Syndrome
    4. Thyroid exam
    5. Skin Exam
       1. Erythema Nodosum
          1. Consider Inflammatory Bowel Disease
    6. Abdominal exam
       1. Benign Abdomen despite severe pain
          1. Consider Mesenteric Ischemia (especially if grossly bloody stool)
       2. Bowel sounds
          1. Hyperactive bowel sounds
             1. Typical in Diarrheal illness
          2. Hypoactive bowel sounds
             1. Bowel Obstruction
    7. Rectal exam
       1. Anal Fissures
          1. Consider Inflammatory Bowel Disease
       2. Bloody stool (occult or gross)
          1. Consistent with Acute Inflammatory Diarrhea
          2. Concurrent fever, Abdominal Pain, tenesmus also suggest Acute Inflammatory Diarrhea
          3. Consider Inflammatory Bowel Disease
          4. Consider Mesenteric Ischemia
11. Labs
    1. See specific tests for indications
    2. Precautions
       1. Labs are expensive and do not alter management in most cases (in the United States)
       2. Directed history and exam are most useful
    3. General indications for lab testing
       1. Dysentery (Bloody Diarrhea, Fever, Abdominal Pain, Tenesmus)
       2. Persistently more than 6 stools daily
       3. More than 1 week of symptoms without improvement
       4. Hospital admission for Dehydration
       5. Age over 65 years
       6. Immunocompromised status
       7. History suggestive of specific Parasite or pathogen
       8. High risk patient
          1. Age >65 years old
          2. Infant <12 months
          3. Pregnancy
          4. Immunocompromised state
          5. Men who have Sex with Men
    4. Labs performed as indicated
       1. Enteric Pathogens Nucleic Acid Test Panels (PCR)
          1. May include Campylobacter, Salmonella, Shigella, Vibrio, Yersina, Norovirus, Rotavirus, Shiga-Toxin
       2. Stool Antigens
          1. Giardia lambliaAntigen
             1. Indicated for Diarrhea >7 days and >10 stools/day
          2. CryptosporidiumAntigen
             1. Immunocompromised patients
          3. Clostridium difficile Toxin
             1. Follows hospitalization for >3 days or
             2. Antibiotic use within prior 3 months
          4. RotavirusAntigen
             1. Indicated for defining local outbreak
       3. Medication levels
          1. Theophylline level
          2. Lithium level
       4. Pregnancy Test
          1. Consider in all women of reproductive age with significant gastrointestinal symptoms
       5. Serum Electrolytes (basic metabolic panel)
          1. Normal in 99% of young, healthy adults with Acute Gastroenteritis in the first 24 hours
             1. Olshaker (1989) Ann Emerg Med 18(3): 258-60 [PubMed]
          2. Indications
             1. Prolonged Diarrhea
             2. Dehydration requiring IV fluids
             3. Toxic or ill appearance
             4. Serious comorbid condition
          3. Findings
             1. Hyponatremia
             2. Hypernatremia
             3. Metabolic Acidosis
             4. Hypoglycemia
       6. Other testing to consider
          1. Hepatitis A Serology
    5. Older tests that have mostly been replaced in U.S. by more specific testing as above
       1. Fecal Leukocytes
          1. Stool Guaiac has the same Positive Predictive Value to identify Bacterial Diarrhea
          2. Bloody stool without Fecal Leukocytes suggests E coli 0157:H7 or Entamoeba histolytica
       2. Stool Culture
          1. Replaced by Enteric Pathogens Nucleic Acid Test Panels (PCR)
          2. Expensive and very low test senstitivity (5%)
          3. Indications
             1. Toxic appearance
             2. Prolonged Diarrhea >4 days
             3. Blood or pus in stool (or other signs of Inflammatory Diarrhea)
             4. Immunocompromised patients
       3. Ova and Parasites
          1. Low yield (requires multiple samples)
          2. Specific Stool ParasiteAntigens are preferred with better accuracy
          3. Indications
             1. Travel to developing countries
             2. Watery Diarrhea >7 days
12. Evaluation: Labs for specific presentations
    1. See Labs and Endoscopy below
    2. Inflammatory Diarrhea or Dysentery
       1. Enteric Pathogens Nucleic Acid Test Panels (PCR) or Stool Cultures (SSCE)
          1. Salmonella including Salmonella typhi
          2. Shigella
          3. Campylobacter
          4. Escherichia coli 0157:H7 (STEC: Shiga Toxin E coli)
             1. Shiga Toxin (if bloody stool)
             2. Avoid antimicrobial agents
       2. Clostridium difficile Toxins
          1. Indicated for recent antibiotics or Chemotherapy
       3. Consider antibiotic coverage (if not STEC)
          1. Quinolone if suspected Shigellosis
          2. Macrolide for suspected Campylobacter
    3. Nosocomial Diarrhea (after 3 days of hospitalization)
       1. Clostridium difficile Toxins
       2. Enteric Pathogens Nucleic Acid Test Panels (PCR) or SSCE culture
          1. Especially if nosocomial outbreak, age over 65 years, comorbidity or Immunocompromised
       3. Discontinue antibiotics if possible
       4. Consider Flagyl if worsens or persists
    4. Persistent Diarrhea >7 days (esp. Immunocompromised)
       1. Fecal Lactoferrin (preferred over Fecal Leukocytes)
          1. High Test Sensitivity for SSCE Bacteria (up to 93%) as well as increased in Inflammatory Bowel Disease
       2. Parasitic Infection evaluation (esp. if adominal bloating, Eructation, Nausea)
          1. Giardia
          2. Cryptosporidium
          3. Cyclospora
          4. Isospora belli
    5. Immunocompromised
       1. See Diarrhea in HIV
       2. Consider Clostridium difficile Toxin (especially if recent antibiotics or hospitalization)
       3. Consider Nucleic Acid Amplification Tests or SSCE Stool Culture (especially if Inflammatory Diarrhea)
       4. Consider Parasitic Infections (e.g. Cryptosporidium, especially if present >7 days)
       5. Consider other opportunistic infections (especially in HIV positive patients)
          1. Microsporidia
          2. Mycobacterium Avium Intracellulare Complex
          3. Cytomegalovrius
13. Evaluation: Endoscopy
    1. Indications
       1. Unclear diagnosis with persistent symptoms
       2. Suspected Tuberculosis
       3. Diffuse colitis (e.g. Clostridium difficile)
       4. Noninfectious Diarrhea cause evaluation (e.g. Inflammatory Bowel Disease)
       5. Does not distinguish Infectious from Inflammatory Diarrhea
    2. Sexually Transmitted Disease (STD)
       1. Lesions in Distal 15 cm in homosexual men
       2. Herpes Virus
       3. NeisseriaGonorrhea
          1. Nonspecific findings limited to Rectum
          2. Biopsy and Culture show superficial exudates
       4. Syphilis
          1. Rectal Papules, Chancres, and ulcers
       5. Chlamydia (Lymphogranuloma venereum)
          1. Similar to Inflammatory Bowel Disease
14. Management: Vomiting
    1. See Vomiting
    2. See Antiemetic
    3. See Vomiting Management in Children
    4. See Vomiting in Pregnancy
15. Management: General
    1. See Diarrhea Management in Children
    2. See Traveler's Diarrhea Management
    3. Electrolyte solutions containing Glucose (not Artificial Sweetener)
       1. Glucose assists with water reabsorption
       2. Oral Rehydration Solution (ORS) is preferred but may not be tolerated well
          1. See Oral Rehydration Solution
          2. Pedialyte, Rehydrate or Infalyte in children
       3. Gatorade or similar
          1. May be used as alternative (but not ideally formulated to match Diarrheal losses)
          2. Requires 1:1 dilution with water to half strength
    4. Dietary guidance
       1. Early reintroduction of food is recommended
          1. Decreases Diarrhea severity and duration
          2. Restores nutritional status earlier
          3. Duggan (1997) J Pediatr 131(6): 801-8 [PubMed]
       2. BRAT diet
          1. Includes Bananas, rice, apple sauce, toast, soup, crackers
          2. Reasonable and non-harmful, but not evidence-based
          3. Likely too restrictive, and patients are now encouraged to eat what they will tolerate
       3. Avoid provocative agents that worsen Diarrhea
          1. Caffeine
          2. Sorbitol
          3. Lactose and dairy products
             1. Typically restricted with Diarrheal illness, but not an evidence-based recommendation
    5. Adjunctive measures
       1. Probiotics
          1. Show benefit in Pediatric Diarrhea, but not verified in adults
          2. Consider Lactobacillus GG (Culturelle) or Saccharomyces boulardii (Florastor)
       2. Zinc
          1. Effective in reducing severity of Pediatric Diarrhea in developing countries, but not evaluated in adults in U.S.
    6. Antidiarrheal medications
       1. Loperamide (Imodium)
          1. Do not use Loperamide if fever or bloody stool are present (Inflammatory Diarrhea)
       2. Bismuth Subsalicylate (Pepto-Bismol)
          1. May be used in Inflammatory Diarrhea
          2. Contraindicated in children
16. Management: Antibiotics
    1. Use is controversial with potentially serious complications (e.g. Hemolytic Uremic Syndrome)
    2. Advantages
       1. Antibiotics appear to shorten Diarrhea course by 24 hours
       2. Effect is regardless of stool guiaic, fecal Leukocyte or Stool Culture result
    3. Disadvantages
       1. Increased Antibiotic Resistance
       2. Increased risk of prolonged carrier state with certain infections (e.g. Salmonella)
       3. Increased risk of developing Hemolytic Uremic Syndrome with E. coli 0157:H7
       4. Increased risk of Clostridium difficile
    4. Contraindications
       1. Grossly bloody Diarrhea or other signs of Escherichia coli 0157:H7 (STEC: Shiga Toxin E coli)
          1. Risk of Hemolytic Uremic Syndrome increases with antibiotic use
    5. Indications
       1. Findings suggestive of Bacterial Diarrhea
          1. Guiaic positive stool (not grossly bloody stool)
          2. Fecal Leukocyte positive
       2. Overseas travel
       3. Diarrheal illness lasting longer than 10-14 days
       4. Immunocompromised patients
       5. Severe illness or Sepsis
       6. Age over 65 years old
    6. Empiric Antibiotics
       1. Ciprofloxacin (adults)
          1. Empiric adult dose: 500 to 1000 mg once or 500 mg twice daily for 3 days
          2. Preferred agent for E. coli (ETEC, EIEC), Shigella
          3. Also covers Campylobacter, Salmonella, Yersinia, Cryptosporidium
       2. Trimethoprim-Sulfamethoxazole (Septra, Bactrim)
          1. Empiric adult dose: One DS twice daily for 3-5 days
          2. Preferred agent for Cyclospora or Isospora
          3. Also covers E. coli (ETEC, EIEC), Salmonella, Shigella, Vibrio Cholerae, Yersinia (Septra has higher resistance rates)
       3. Azithromycin
          1. Empiric adult dose: 500 mg daily for 3 days
          2. Preferred agent for Campylobacter
          3. Also covers E. coli (ETEC), Salmonella, Shigella, Vibrio Cholerae
       4. Third generation Cephalosporin (e.g. Cefdinir, Cefpodoxime)
          1. Consider in children for Shigella, Salmonella
    7. Other antibiotics used for specific indications
       1. Metronidazole
          1. Preferred agent for Entamoeba histolytica, Giardia
          2. Alternative agent for Clostridium difficile (but high failure rate)
       2. Azithromycin
          1. Campylobacter (treat with 3-5 day course)
       3. Ciprofloxacin
          1. Non-Typhoidal Salmonella (other Fluoroquinolones are also effective)
          2. Shigella (Reduces duration and shedding)
       4. Doxycycline
          1. Preferred agent for Vibrio Cholerae
          2. Also covers Yersinia (when combined with an Aminoglycoside)
       5. Oral Vancomycin
          1. Preferred agent for Clostridium difficile
    8. Antiparasitic agents used for specific indications
       1. See Metronidazole indications above
       2. Albendazole (Albenza)
          1. Preferred agent for Microsporida
       3. Tindazole (Tindazole)
          1. Covers Entamoeba histolytica (when treated in combination with Paromomycin)
          2. Also covers Giardia
       4. Nitazoxanide (Alinia)
          1. Covers Cryptosporidium
17. Management: Admission Criteria
    1. Severe Diarrhea with difficulty maintaining hydration
    2. Very young or very old
    3. Severe comorbid illness
    4. Severe pain
    5. High fever
    6. Intractable Vomiting
18. Prevention
    1. See Water Disinfection
    2. See Traveler's Diarrhea Prevention
    3. See Foodborne Illness Prevention
    4. Hand Washing
       1. Decreases Infectious Diarrhea Incidence by one third
       2. Ejemot (2008) Cochrane Database Syst Rev (1):CD004265 [PubMed]
    5. Healthcare workers and food workers should not return to work until symptoms have resolved for 48 hours
    6. Vaccinations
       1. Rotavirus (part of Primary Series in U.S.)
       2. Typhoid Fever (frequently required for overseas Travel Immunizations)
       3. Cholera
    7. CDC Reportable Illnesses (National Notifiable Diseases Surveillance System or NNDSS)
       1. https://wwwn.cdc.gov/nndss/data-and-statistics.html
       2. Listeria
       3. Typhoid Fever (Salmonella typhi)
       4. Trichinellosis
       5. Cyclospora
       6. Vibrio
       7. Shiga-toxin producing E. coli (e.g. E. coli 0157:H7, Enterohemorrhagic E. coli)
       8. Giardiasis
       9. Foodborne Botulism
       10. Shigella
       11. Post-Diarrhea; Hemolytic Uremic Syndrome
19. Resources
    1. IDSA Clinical Practice Guidelines for the Diagnosis and Management of Infectious Diarrhea (2017)
       1. https://academic.oup.com/cid/article/65/12/e45/4557073
20. References
    1. Glauser and Schafer (2020) Crit Dec Emerg Med 34(1):3-12
    2. May and Mason in Herbert (2021) EM:Rap 21(6): 15-6
    3. Herbert (2012) EM:RAP-C3 2(4): 2
    4. Barr (2014) Am Fam Physician 89(3): 180-9 [PubMed]
    5. Guerrant (2001) Clin Infect Dis 32:331-48 [PubMed]
    6. Scallen (2011) Emerg Infect Dis 17(1): 7-15 [PubMed]