Diarrhea : Clinicals Flashcards
How is acute diarrhea classified?
Acute diarrhea is classified as lasting for less than 2 weeks.
How is persistent diarrhea classified?
Persistent diarrhea is classified as lasting for 2 to 4 weeks.
How is chronic diarrhea classified?
Chronic diarrhea is classified as lasting for more than a month.
How can diarrhea be classified based on inflammation?
Diarrhea can be classified as either inflammatory or non-inflammatory.
Describe : Inflammatory diarrhea (3)
- Inflammatory diarrhea is caused by inflammation of the gastrointestinal epithelium
- usually associated with invasive pathogens or chronic inflammatory bowel disease.
- Systemic symptoms like fever may also be present.
Describe : Non-inflammatory diarrhea (2)
- Non-inflammatory diarrhea can be either secretory or osmotic
- does not usually cause systemic symptoms like fever.
What happens in secretory diarrhea?
- increased water and electrolyte secretion
- decreased absorption.
What happens in osmotic diarrhea? (2)
- Osmotic diarrhea occurs when ingested nutrients aren’t fully absorbed
- leading to water being pulled into the intestinal lumen through osmosis.
What are the common causes of acute diarrhea? (2)
- Mostly caused by pathogens including viruses, bacteria, protozoa, and parasites, which spread through fecal-oral transmission.
- Non-infectious causes of acute diarrhea include stress, medications, or toxic ingestion.
What pathogens are associated with non-inflammatory, secretory diarrhea?
Viruses such as norovirus and rotavirus cause non-inflammatory, secretory diarrhea with watery stools and vomiting.
How can food poisoning be identified based on the timing of diarrhea? (3)
- If diarrhea occurs within 6 hours of ingestion : may be caused by Staphylococcus aureus or Bacillus cereus.
- 8 to 16 hours after ingestion : may be Clostridium perfringens.
- More than 16 hours after ingestion : may be enterotoxigenic E. coli.
What are the characteristics of inflammatory diarrhea? (4)
Inflammatory diarrhea is associated with
* bloody and mucousy stools
* severe abdominal pain
* fever.
* It is caused by invasive pathogens like Salmonella, Shigella, Yersinia, Campylobacter, and enteroinvasive E. coli (SSYCE).
What is the association between Salmonella infection and contaminated foods?
Exposure to contaminated animal products like meat, dairy, and eggs has been associated with Salmonella infection.
What infection is associated with drinking contaminated water?
Drinking contaminated water can lead to a Giardia infection.
Which bacterium may be responsible for pseudomembranous colitis after recent antibiotic use?
Clostridium difficile may be the culprit, causing pseudomembranous colitis after recent antibiotic use.
When are laboratory tests usually done in individuals with acute diarrhea?
Laboratory tests are not usually done in individuals with acute diarrhea unless there are signs of moderate or severe dehydration.
Which laboratory tests are recommended in cases of severe dehydration to rule out renal dysfunction?
In cases of severe dehydration, electrolytes, creatinine, and urea nitrogen should be taken to rule out renal dysfunction.
When might a complete blood count (CBC) be helpful in acute diarrhea cases? (2)
- Thrombocytopenia and anemia are suggestive of hemolytic-uremic syndrome caused by E. coli O157 which produces Shiga toxin.
- An elevated white blood cell count can be seen in Clostridium difficile infections.
When should a more thorough workup be considered for acute diarrhea cases?
A more thorough workup should be considered for individuals who are ill appearing, vulnerable populations (e.g., elderly, comorbid conditions), or in fields that could cause a public health concern (e.g., daycare workers).
What are some tests recommended for a more thorough workup of acute diarrhea? (4)
- Blood cultures
- Fecal leukocytes or fecal lactoferrin (to differentiate inflammatory from non-inflammatory diarrhea)
- Stool cultures for SSYCE, C. diff toxin assays, enterohemorrhagic E. coli Shiga toxin, and Entamoeba histolytica testing (sending three stool specimens on consecutive days)
- Testing for common viruses like norovirus and rotavirus is also recommended.
What is the main treatment for acute infectious diarrhea?
- Fluid repletion : oral rehydration solutions taken orally or via a nasogastric tube. In severe cases, individuals with severe hypovolemia may be given intravenous fluids.
- Dietary adjustments : Simple and liquid food. Dairy products like milk and cheese should be avoided for a few months because acute infectious diarrhea often causes secondary lactose malabsorption. Live culture yogurt is an exception because it contains live active bacteria that help break down and digest lactose in milk.
When is empiric antibiotic treatment given in acute diarrhea cases?
Empiric antibiotic treatment is given to individuals who are severely ill, have risk factors for complications, or if the onset of symptoms was travel-associated.
What are some common empiric antibiotic regimens for acute diarrhea?
- Azithromycin 500mg once daily for three days
- Fluoroquinolones such as ciprofloxacin 500mg twice daily for 3 to 5 days.
Why shouldn’t antibiotics be used to treat enterohemorrhagic E. coli infections?
because they increase the toxicity of E. coli’s Shiga toxin.
