Acute Diarrhea | Approach to Causes, Enterotoxic vs Invasive, Watery vs Bloody Diarrhea

Summary

This lesson focuses on an approach to acute diarrhea, covering its definitions, types, and causes. Diarrhea is classified by increased bowel movement frequency, decreased stool consistency, or dry stool weight. The video explains how diarrhea is categorized as acute (less than two weeks) or chronic (over two weeks) and explores the various factors that can contribute to acute diarrhea, including travel history, food intake, medications, and infections. The pathogenesis and symptoms of both enterotoxic (non-inflammatory) and invasive (inflammatory) diarrhea are discussed, along with common bacterial, viral, and protozoan causes.

Takeaways

• 💩 Diarrhea is defined by three criteria: increased bowel movement frequency or decreased stool consistency, producing at least 200 grams of stool per day, or having three or more bowel movements per day.
• ⏳ Acute diarrhea lasts less than two weeks and is often caused by infections like bacteria, viruses, or protozoa. Chronic diarrhea lasts more than two weeks and may indicate underlying conditions like Crohn's disease.
• 🌍 Travel history, recent food intake, and antibiotic use can help determine the cause of acute diarrhea, especially for travelers’ diarrhea or foodborne infections.
• 🤒 Acute diarrhea can be categorized into enterotoxic (non-inflammatory) and invasive (inflammatory) types based on symptomology and pathogenic mechanisms.
• 🚰 Enterotoxic diarrhea (non-inflammatory) is characterized by watery stools, no fever, and is often caused by a toxin, such as in E. coli, C. difficile, and Vibrio cholerae infections.
• 🩸 Invasive diarrhea (inflammatory) features bloody stools, fever, and increased white blood cells, caused by pathogens like Salmonella, Shigella, and Campylobacter.
• 🔬 In enterotoxic diarrhea, toxins disrupt the gut's absorption, causing water and ions to leak into the intestines, leading to watery diarrhea.
• 🔥 In invasive diarrhea, bacteria penetrate and damage intestinal lining, leading to inflammation, fever, and bleeding, often causing bloody diarrhea.
• 🧫 Common enterotoxic causes include E. coli (especially traveler’s diarrhea), Clostridium difficile (linked to antibiotic use), Vibrio cholerae, and Giardia lamblia (often from contaminated water).
• 🍗 Invasive diarrhea causes include Salmonella (often from poultry), Shigella (uncooked vegetables), and enterohemorrhagic E. coli (contaminated meat), all potentially leading to serious complications.

Q & A

What are the three definitions of diarrhea mentioned in the lesson?

The first definition is any increased frequency of bowel movements or decreased consistency of stool in a 24-hour period. The second is having at least 200 grams of dry weight of stool per day, though this is difficult to quantify. The third definition is having at least three bowel movements per day.

How is acute diarrhea different from chronic diarrhea?

Acute diarrhea lasts less than two weeks and is usually caused by infectious agents like bacteria or viruses. Chronic diarrhea lasts more than two weeks and is often linked to chronic medical conditions like Crohn's disease, ulcerative colitis, or irritable bowel syndrome.

Why is it important to distinguish between acute and chronic diarrhea?

It's important because acute diarrhea is usually caused by infections, whereas chronic diarrhea is more likely to be caused by underlying medical conditions. This helps in determining the right treatment approach.

What factors are considered when determining the cause of acute diarrhea?

Factors include travel history, contact with sick individuals, recent food intake, recent hospitalization, recent antibiotic use, past medical history of diarrhea, symptom progression, and medication use (especially laxatives).

What are the two main categories of acute diarrhea causes?

The two main categories are enterotoxic (non-inflammatory) and invasive (inflammatory) causes.

What is the pathogenic mechanism behind enterotoxic acute diarrhea?

In enterotoxic acute diarrhea, there's usually malabsorption of nutrients or ions, or an efflux of ions like chloride into the gastrointestinal lumen, leading to watery diarrhea. This is often toxin-mediated without invasion of tissues, so there's no inflammation or fever.

What is the pathogenic mechanism behind invasive acute diarrhea?

In invasive acute diarrhea, infectious agents penetrate and invade the gastrointestinal lining, leading to tissue damage, inflammation, bleeding, and often a fever. This can result in bloody diarrhea and an immune response.

What are common causes of enterotoxic (non-inflammatory) acute diarrhea?

Common causes include enterotoxic E. coli (travelers’ diarrhea), Clostridium difficile (linked to recent antibiotic use), Vibrio cholerae (contaminated water), Giardia lamblia (camping or untreated water), Staphylococcus aureus (food poisoning), and Bacillus cereus (uncooked or reheated rice). Viruses like norovirus and rotavirus can also cause it.

What are common causes of invasive (inflammatory) acute diarrhea?

Common causes include Salmonella (uncooked or undercooked poultry), Shigella (raw vegetables, unpasteurized dairy), enterohemorrhagic E. coli (E. coli O157:H7 from undercooked meat), Campylobacter jejuni (undercooked poultry), and Entamoeba histolytica (more common in immunocompromised patients).

How do symptoms differ between enterotoxic and invasive acute diarrhea?

Enterotoxic diarrhea causes watery diarrhea without fever, leukocytosis, or fecal white blood cells, while invasive diarrhea causes bloody diarrhea, fever, leukocytosis, and fecal white blood cells due to tissue invasion and inflammation.