Acute Diarrhea
last authored: Oct 2009, David LaPierre
Introduction
Acute diarrhea lasts less than 2-3 weeks, while chronic diarrhea remains longer than this period.
Diarrhea can be difficult to fully define, as different people have different bowel habits. It is a subjectively increased frequency or decreased consistency, and should be >300 grams/day to be accurately called diarrhea.
In infants, up to 7 stools daily.
In adults, 1.2 BM daily is normal. Avg is 10 ml/kg.
The Case of...
Differential Diagnosis
Viral (most common)
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Bacterial
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Parasites |
Diarrhea can be secretory or osmotic.
History and Physical Exam
- history
- physical exam
History
features of viral infection
- URTI
- resolves in 3-7 days
- slight fever
- malaise
- vomiting
- vague abdominal pain
features of bacterial infection
- severe abdominal pain
- high fever
- bloody diarrhea
- risk factors
Sometimes, what people consider diarrhea is actually incontinence. Explore this possibility as appropriate.
volume of diarrhea (amount, ie in cups x number)
bloody vs non-bloody
dietary (poorly cooked or refrigerated foods, non-absorbable sugars, lactose intolerance)
travel
recent start to medications
background of constipation
Physical Exam
Vitals, especially temperature and dehydration status
DRE
signs of peritonitis
extraintestinal manifestations of IBD: arthritis, apthous ulcers, erythema nodosum, iritis, scleritis, ankylosing spondylitis, pyoderma gangrenosum, clubbing
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
blood tests
- CBCD
- electrolytes
- urea and creatinine
- Anti-tissue transglutaminase (for celiac disease)
Stools
- O & P
- C & S
- C difficile toxin
- electron microscopy for viruses
blood, urine cultures should be done if disease is severe
Diagnostic Imaging
Management
Most cases of mild-to-moderate diarrhea are self-limiting. Avoid further transmission of disease by encouraging proper handwashing and personal hygiene and disinfection of contaminated objects.
Oral rehydration
oral rehydration solution
in mmol/L - total Osm 245
- Sodium: 75
- Glucose, anhydrous: 13.5
- Chloride: 65
- Potassium: 20
- Citrate: 10
ORS contains electrolytes and carbohydrate, as sugar enhances sodium reabsorption, and water follows. Rice-based rehydration fluids work best to provide rehydration and slow diarrhea.
Frequent, small volumes of rehydration solutions should be given, with normal feeding should be restarted as soon as possible.
Zinc can also significantly reduce diarrheal output.
Loperimide can be used for symptom control for non-severe diarrhea. However, as diarrhea is a mechanism to expel pathogens, anti-diarrheal medications can be dangerous and have led to toxic megacolon and HUS in children infected with E coli 0157.
In adults, usual dose is 4mg to start and 2mg after each subsqeuent loose stool, to a maximum of 16 mg daily.
Antibiotics
Avoid antibiotics unless C difficile is found, if dysentry is present, at extremes of age, or if patient is very unwell.
C. difficile should be treated with metronidazole or vancomycin, while gram-negativebacteria can be treated with a fluoroquinolone such as ciprofloxacin.
Pathophysiology
Involvement of the distal 25 cm of the iluem will impair bile
Osmotic is the most common cause
Secretory
inflammatory.
The Case of...
Additional Resources
Rehydrate.org - homemade solutions
Topic Development
created: DLP, Aug 09
authors: DLP, Aug 09
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