Gastroenterology- Diarrhoea Flashcards
What defines diarrhea?
Diarrhea is characterized by the passage of abnormally liquid or unformed stools, which take the shape of the container, and an increased frequency of bowel movements (more than 3 times per day) with a stool weight exceeding 200 grams per day.
Why are the limits for diarrhea set at >3 times per day and >200 grams?
These limits help distinguish between normal bowel function and pathological conditions. The criteria reflect changes in stool consistency and frequency that are typically associated with gastrointestinal disturbances.
What is pseudo-diarrhea?
Pseudo-diarrhea refers to frequent bowel movements that may occur with normal stool consistency, often related to increased urgency or anxiety rather than true diarrhea.
What is fecal incontinence?
Fecal incontinence is the inability to control bowel movements, resulting in involuntary passage of stool. This can occur alongside or independently of diarrhea.
What is the Bristol stool chart?
The Bristol stool chart is a diagnostic tool that classifies stools into seven types based on consistency and shape, helping to assess bowel health and identify conditions such as constipation and diarrhea.
What are the seven types of stool in the Bristol stool chart?
Type 1:
Description: Separate hard lumps, like nuts (difficult to pass).
Indicates: Severe constipation.
Type 2:
Description: Sausage-shaped but lumpy.
Indicates: Mild constipation.
Type 3:
Description: Sausage-shaped with cracks on the surface.
Indicates: Normal stool, but may indicate a need for increased fiber.
Type 4:
Description: Smooth, soft sausage or snake.
Indicates: Normal, healthy stool.
Type 5:
Description: Soft blobs with clear-cut edges (passed easily).
Indicates: Lacking fiber; may indicate a need for more solid food.
Type 6:
Description: Fluffy pieces with ragged edges; a mushy stool.
Indicates: Mild diarrhea or gastrointestinal upset.
Type 7:
Description: Watery, no solid pieces (entirely liquid).
Indicates: Severe diarrhea; likely requires medical evaluation.
What is acute diarrhea?
Acute diarrhea is characterized by the sudden onset of loose or watery stools lasting less than 2 weeks, often due to infections (viral, bacterial, or parasitic) or foodborne illnesses.
What defines persistent diarrhea?
Persistent diarrhea lasts between 2 to 4 weeks and can be caused by ongoing infections, inflammatory bowel diseases, or malabsorption syndromes.
What is chronic diarrhea?
Chronic diarrhea is defined as diarrhea lasting more than 4 weeks. It can result from chronic conditions such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), celiac disease, or certain medications.
What is the underlying mechanism of acute diarrhea?
Acute diarrhea occurs when the cause overwhelms or bypasses the host’s mucosal immune and non-immune defenses, such as gastric acid, digestive enzymes, mucus secretion, peristalsis, and suppressive resident flora.
ow can the pathophysiology of the agent causing acute diarrhea aid in diagnosis?
Understanding the pathophysiology can help identify whether diarrhea is caused by ingested preformed bacterial toxins or entero-adherent pathogens, which can influence treatment and management.
What are the symptoms of acute diarrhea caused by preformed bacterial toxins?
Symptoms typically include profuse, watery diarrhea occurring within a few hours, often with less vomiting and minimal fever.
What are the characteristics of acute diarrhea caused by cytotoxins and invasive organisms?
This type may present with high fever, abdominal pain, and dysentery (bloody stools), indicating more severe infection.
What systemic manifestations may follow certain bacterial infections related to acute diarrhea?
Conditions such as reactive arthritis, urethritis, and conjunctivitis (Reiter’s syndrome) may follow infections from organisms like Shigella, Salmonella, Campylobacter, and Yersinia.
What severe systemic infections can be associated with acute diarrhea?
Severe systemic infections can include hepatitis, legionellosis, and toxic shock syndrome, depending on the infectious agent.
What percentage of acute diarrhea cases is attributed to infectious causes?
Over 90% of acute diarrhea cases are infectious, often presenting with symptoms like abdominal cramps, fever, and vomiting.
What are some common risk factors for infectious acute diarrhea?
Recent travel
Consumption of certain foods (e.g., undercooked or contaminated food)
Immunodeficiency
Daycare attendance or exposure to family members with diarrhea
Being institutionalized (e.g., in nursing homes)
What other factors can contribute to acute diarrhea aside from infections?
Other factors contributing to acute diarrhea may include:
Medications: Such as antibiotics that disrupt gut flora.
Toxins: From foodborne pathogens or chemical exposure.
Ischemia: Reduced blood flow to the intestines, causing diarrhea.
What percentage of travelers to third-world regions or tropics develop traveler’s diarrhea?
Approximately 40% of travelers to third-world regions or tropics develop traveler’s diarrhea.
What are the common causative agents of traveler’s diarrhea?
Enterotoxigenic Escherichia coli (ETEC)
Enteroaggregative Escherichia coli (EAEC)
Campylobacter
Giardia
Shigella
Aeromonas
Norovirus
Coronavirus
Salmonella
What symptoms are typically associated with traveler’s diarrhea?
Watery diarrhea
Abdominal cramps
Nausea and vomiting
Fever (in some cases)
What is consumer diarrhea commonly associated with?
Consumer diarrhea is often linked to food poisoning from contaminated food or beverages.
What are common pathogens causing consumer diarrhea?
Salmonella
Shigella
Enterohemorrhagic E. coli
Bacillus cereus
Staphylococcus aureus
Vibrio species
Salmonella
Often found in banquet foods, eggs, creams, and seafood.
Shigella
A cause of foodborne illness linked to contaminated food and water.
Enterohemorrhagic E. coli (EHEC)
Typically associated with undercooked beef.
Bacillus cereus
Often linked to fried rice.
Staphylococcus aureus
Commonly found in mayonnaise and creams.
Vibrio species
Typically associated with contaminated water.
What symptoms are generally seen in consumer diarrhea cases?
Symptoms typically include:
Watery or bloody diarrhea
Abdominal pain and cramps
Nausea and vomiting
Fever (in some cases)
What types of immunodeficiency syndromes are there?
There are both primary immunodeficiency syndromes (inherited) and secondary immunodeficiency syndromes (acquired due to factors like infections, medications, or diseases).
What are some common infectious agents associated with immunodeficiency syndromes?
Mycobacterium species: Can cause opportunistic infections in immunocompromised individuals.
Opportunistic infections (OIs): Such as Cytomegalovirus (CMV), adenovirus, and herpes simplex virus.
What protozoan infections are commonly seen in immunodeficient patients?
Cryptosporidium: Can cause severe diarrhea in immunocompromised individuals.
Isospora belli: Often seen in those with weakened immune systems.
Microsporidia: Also associated with opportunistic infections in immunodeficiency.
Daycare attendees and family members
Giardia
Shigella
Cryptosporidium
Institutionalized patients
Nosocomial infections
- Clostidium difficile
What are common medications associated with non-infectious acute diarrhea?
Medications that can cause non-infectious acute diarrhea include:
Antibiotics: Disrupt normal gut flora.
Cardiac antiarrhythmics: Can cause gastrointestinal side effects.
NSAIDs (nonsteroidal anti-inflammatory drugs): May irritate the gut lining.
PPIs (proton pump inhibitors): Linked to gastrointestinal disturbances.
Bronchodilators: Occasionally lead to diarrhea.
What is the significance of temporal relationships in non-infectious diarrhea?
A temporal relationship indicates that the onset of diarrhea follows the initiation of medication, suggesting a potential causal link.
What are the characteristics of ischemic colitis?
Ischemic colitis often occurs in older patients with risk factors for vascular disease, presenting with severe abdominal pain and watery diarrhea.
How can diverticulosis lead to non-infectious acute diarrhea?
Diverticulosis can cause inflammation or diverticulitis, which may lead to episodes of diarrhea due to bowel irritation.
What is GVHD, and how does it relate to acute diarrhea?
Graft-versus-host disease (GVHD) can occur after stem cell or organ transplants, leading to immune-mediated damage to the gastrointestinal tract, resulting in diarrhea.
