Diarrhea
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.
Causes of Acute Diarrhea
Most cases of acute diarrhea are infectious.
Viral
|
Bacterial
|
Parasites |
Diarrhea can be secretory or osmotic.
Approach to Diarrhea
- History
- Physical Exam
- Lab Investigations
- Imaging
History
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 (previous meals, non-absorbable sugars, lactose intolerance)
travel
recent start to medications
- can be
background of constipation
Physical Exam
Assume vitals, especially temperature and volume
DRE
signs of peritonitis
extraintestinal manifestations of IBD: arthritis, apthous ulcers, erythema nodosum, iritis, scleritis, ankylosing spondylitis, pyoderma gangrenosum, clubbing
Lab Investigations
blood tests
- CBCD
- electrolytes
- urea and creatinine
- Anti-tissue transglutaminase (for celiac disease)
Stools
- O & P
- C & S
- C difficile toxin
blood cultures should be done if
Imaging
Abdominal series
sigmoidoscopy, especially for persistent diarrhea
Involvement of the distal 25 cm of the iluem will impair bile
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
Solutions should include electrolytes and carbohydrate. Carbohydrates enhance sodium reabsorption, and water follows.
Rice-based rehydration fluids work best to provide rehydration and slow diarrhea. (GET WHO RECIPE FOR THIS).
Normal feeding should be restarted as soon as possible.
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 of Diarrhea
Osmotic is the most common cause
Secretory
inflammatory