Acute diarrhea

Background

• 85% of diarrhea is infectious in etiology
• Almost all true diarrheal emergencies are of noninfectious origin
• Definitions
  • Diarrhea: Increased frequency of defection, usually >3 bowel movements per day
  • Hyperacute: 1-6 hr
  • Acute: less than 3 wks in duration
  • Gastroenteritis: Diarrhea with nausea and/or vomiting
  • Dysentery: Diarrhea with blood/mucus/pus
  • Invasive = Infectious

Diagnosis

DDX Emergent

1. Appendicitis
2. Mesenteric ischemia
3. Ectopic
4. CO poisoning
5. SAH
6. Diverticultis

History

1. Possible food poisoning?
2. Does it resolve (osmotic) or persist (secretory) w/ fasting?
3. Are the stools of smaller volume (large intestine) or larger volume (small intestine)
4. Fever or abdominal pain? (diverticulitis, gastroenteritis, IBD)
5. Bloody or melenic?
6. Tenesmus? (shigella)
7. Malodorous? (giardia)
8. Recent travel?
9. Recent Abx?
10. HIV/immunocomp/sexual hx
11. Heat intolerance and anxiety? (thyrotoxicosis)
12. Paresthesias or reverse temperature sensation? (ciguatera)

Physical Exam

1. Thyroid masses
2. Oral ulcers, erythema nodosum, episcleritis, anal fissure (IBD)
3. Reactive arthritis (Arthritis, conjunctivitis, urethritis)
   1. Suggests infx w/ salmonella, shigella, campylobacter, or yersinia
4. Rectal exam for fecal impaction
5. Guaiac
6. Abdominal pain out of proportion to exam (mesenteric ischemia)

Work-Up

Only indicated for:

• Diarrhea a/w severe abdominal pain and fever
• Symptoms >3d
• Blood or pus in stool
• Immunocompromised pts
• Systemic illness

1. Fecal leukocytes
   1. Used to differentiate invasive from noninvasive infectious diarrheas
   2. Sn 50-80%, Sp 83% for presence of bacterial pathogen
   3. If pt has +leukocytes but negative infection consider IBD
2. Stool culture
   1. Plays minor role in ED evaluation
   2. Yield is only 1.5-5.5%
3. O&P
   1. Indicated if parasitic cause is suspected
      1. Untreated water, diarrhea >7d
4. C. diff toxin
   1. 10% false negative rate
   2. Takes 24hr to run
5. Chemistry
   1. Warranted in severely ddhydrated pts
6. Abd x-ray
   1. Consider if h/o abdominal sx (r/o obstruction)
7. CXR
   1. Consider if diarrhea + cough (Legionella)
8. CT
   1. Consider if suspect mesenteric ischemia

Treatment

1. Oral rehydration
2. Food avoidance:
   1. Caffeine (incr gastric motility), raw fruits (increases osmotic diarrhea), lactose

Toxigenic v. Infectious

Characteristic	Toxic	Infectious/Invasive
Incubation	2-12h	1-3d
Onset	abrupt	gradual
Duration	<10-24h	1-7days
Fever	No	Yes
Abdominal Pain	Minimal	Yes, tenesmus
Systemic	No	Yes, myalgias, N/V
Physical findings	Nontoxic	Toxic
Abdominal Tenderness	No	Yes
Stool Blood, WBCs	No	Yes

DDX

Noninfectious

• GI bleed
• Adrenal insufficiency
• Thyroid storm
• Toxicologic exposures
• Mesenteric ischemia
• Antibiotic or drug-associated

Infectious

Viruses cause the vast majority of infectious diarrhea A history of foreign travel is associated with an 80% probability of bacterial diarrhea

The presence of severe abdominal pain, fever, or bloody stool mandates microbiologic workup to rule out bacterial or amoebic infection.

If the stool demonstrates fecal leukocytes, there is an increased chance of finding an invasive pathogen. Bloody stool without white blood cells is a common feature of Shiga toxin–producing E. coli or E coli O157:H7 and colitis that is due to E. histolytica.1,6

Patients with severe pain, fever, and bloody stool should undergo stool studies for specific pathogens, including culture for Salmonella, Shigella, Campylobacter, and E coli O157:H7; assay for Shiga toxin; and microscopy or antigen assay for E. histolytica.6

Exposure of a traveler or hiker to untreated water and illnesses that persist for more than 7 days should prompt evaluations for protozoal pathogens. Indeed, one of the major clinical features of protozoal diarrheas is prolonged course. Patients who have persistent diarrhea should have stools tested for E. histolytica antigen, G. intestinalis antigen, and Cryptosporidium parvum antigen by enzyme immunoassay.1,6

For adults with domestically acquired diarrhea in whom the origin is thought to be infectious, antibiotics (500 milligrams of ciprofloxacin by mouth as a single dose for onset of travelers' diarrhea or twice daily for 3 days)8,15 shorten the duration of illness by approximately 24 hours. Regardless of the causative agent, all patients—even those with a negative Wright stain, negative stool culture, and a low diarrheal illness score, suggesting less clinically significant disease and/or a viral cause—improved on ciprofloxacin.16 Even though most infectious diarrheas are self limited, because of the inconveniencing and occasionally life-threatening nature of the disease, we recommend ciprofloxacin treatment for all patients believed to have an infectious diarrhea who do not have a contraindication to antimicrobial treatment (e.g., pediatric age group, allergy, pregnancy, or drug interaction).

Antidiarrheals are effective for the treatment of traveler's diarrhea16 and bacillary dysentery due to Shigella or enteroinvasive E. coli.19 Loperamide (see Table 76-2 for dosing) shortens the duration of symptoms when combined with an antibiotic regimen. Loperamide, bismuth subsalicylate, and kaolin are the only agents that are labeled as antidiarrheals. Although the literature is scant, most authors recommend the avoidance of antimotility agents in the subset of patients with bloody diarrhea or suspected inflammatory diarrhea because of the possibility of prolonged fever, toxic megacolon in C. difficile patients, and hemolytic uremic syndrome in children infected with Shiga-toxin producing E. coli.1

When deciding whether to admit a patient with diarrhea, conservatism should be the rule with the young and the elderly

Work Up

1. Toxigenic:Nothing
2. Invasive:
   1. Stool Cx
      1. Additional Cx: E.Coli 0157:H7
3. C. dif toxin
4. Sool O&P
   1. 1. only if suspect parasitic, recent travel, failed abx, chronic diarrhea, immunocompromised
5. Send stool WBCs only if diagnosis is uncertain; Sensitivity: 60-85% (ie unclear if invasive or toxigenic)

Treatment

Toxigenic

1. Rehydrate with fluids containing sugar, salt, fluids po, IV NS
2. Avoid high osmolality (gatorade!), caffeine, lactose-containing (lactase removed during infection)
3. Eat! - BRAT diet (small amounts banana, rice, apple sauce, toast) - will speed up recovery
4. Analgesia as needed
5. Anti-diarrheals
6. Kaolin-pectin agents
7. Bismuth
8. Antimotility (avoid alone in invasive illness)

Infectious

Above plus:

1. Antibiotics
   1. Ciprofloxacin 500mg po bid or
   2. Levofloxacin 500mg po qd or
   3. Bactrim DS 1tab po bid (+/-)
2. 3-7d treatment

Empiric Abx

1. Toxic appearance
2. Vital abnl
3. Fever >39
4. Bloody diarrhea
5. Severe dehydration

Loperimide Contraindications

1. Pediatric
2. IBD
3. C. Diff
4. Dysentery

(always give with abx)

WHO Oral Rehydration

1. 1 cup orange juice
2. 4 tsp sugar
3. 1 tsp baking powder
4. 3/4 tsp salt
5. in 1 liter of H2O

Other

Octreotide can be used in AIDS-associated diarrhea unresponsive to loperimide

Consider Pepto-Bismol for traveler's diarrhea (contraindicated in HIV-->encephalopathy)

Source

3/12/06 DONALDSON (adapted from Rosen); 09 Birnbaumer