Diarrhoea Flashcards
What is diarrhoea?
Increased frequency and volume of stool and decreased consitency
What would you want to establish in the history in someone who is presenting with acute diarrhoea?
Acute (<2 wks)
- Contact with D+V
- Fever/systemic upset
- Pain
- Blood/mucus
- Travel
- Diet change
- Contact with animals
- Associated symptoms
- Medications
- Social - drugs, alcohol
What would you want to ask in the history in someone who is presenting with chronic diarrhoea?
- Fever/systemic upset
- Pain
- Blood/mucus
- Travel
- Diet change
- Weight loss
- Nocturnal diarrhoea
- Symptoms of anaemia
What are causes of bloody diarrhoea?
- Campylobacter
- Shigella
- Salmonella
- E. Coli
- AMoebiasis
- IBD
- Colorectal cancer
- Colonic polyps
- Pseudomembranous colitis
- Ischaemic colitis
What are causes of diarrhoea with mucus?
- IBS
- Colorectal cancer
- Polyps
What are causes of diarrhoea with franck pus?
- IBD
- Diverticulitis
- Fistula/abscess
What are causes of “explosive” diarrhoea?
- Cholera
- Giardia
- Yersinia
- Rotavirus
What are causes of steatorrhoea?
- Pancreatic insufficiency
- Biliary obstruction
- Coeliac disease
- CF
What are non-GI causes of diarrhoea?
- Thyrotoxicosis
- Autonomic neuropathy
- Addison’s Disease
- Amyloidosis
- Pellagra
- Drugs
What are the common causes of diarrhoea?
- Gastroenteritis
- Traveller’s diarrhoea
- C. dioff
- IBS
- Colorectal cancer
- IBD
- Coeliac
What drugs can cause diarrhoea?
- Antibiotics
- Propranalol
- Cytotoxics
- Laxatives
- PPI’s
- NSAIDs
- Digoxin
- Alcohol
What bacteria can cause diarrhoeal illness?
- Salmonella
- Campylobacter
- E. coli 0157
- Shigella
- Clostridium Difficile
- Cholera
How long after onset do symptoms of Salmonella associated Diarrhoea present?
<48hrs
How long does Salmonella associated diarrhoea normally last for?
<10 days
What are the different types of diarrhoea?
- Osmotic Diarrhoea
- Secretory Diarrhoea
- Inflammatory Diarrhoea
- Abnormal motility
What can prolonged carriage of Salmonella be associated with?
Gallstone formation
What can be a common problem post-infection for someone who has had Salmonella?
Irritable Bowel Syndrome
What species of campylobacter is the main pathogen in diarrhoeal infection?
Campylobacter jejuni
What are the most common sources of campylobacter infection?
- Contaminated Milk
- Chickens
- Puppies
- Water
What is the incubation time for Campylobacter?
2-5 days
What are the main symptoms of Campylobacter infection?
- Severe Abdominal Pain - often becomes continuous and radiates to right iliac fossa
-
Watery Diarrhoea
- Can become bloody
- Fever
- Nausea and Vomiting
How long does it normally take for Campylobacter infection to clear?
3 weeks
How long does it take stools to become negative in Campylobacter infections?
6 weeks
What are some of the long term post-infective sequelae of Campylobacter infection?
- Guillain Barre Syndrome
- Reactive Arthritis
What is secretory diarrhoea?
Both active intestinal secretion of fluid and electrolytes as well as decreased absorption
Cholera toxin is regarded as the classic model of this
What are common causes of secretory diarrhoea?
- Enterotoxins
- Hormones
- Bile salts (in the colon) - following ileal resection
- Fatty acids (in the colon) - following ileal resection
- Some laxatives
What is the pathophysiology of diarrhoea caused by cholera?
- Increases cAMP levels
- Increases protein kinases
- Inhibit Na+ and Cl- absorption
- Cl- secretion
What bacteria cause secretory diarrhoea?
- Cholera
- E. Coli
- C. Difficile
How do you distinguish between secretory and inflammatory diarrhoea?
Inflammatory diarrhoea is accompanied by PAIN AND FEVER
What is osmotic diarrhoea?
Gut mucosa acts as a semipermeable membrane and fluid enters the bowel if there are large quantities of non-absorbed hypertonic substances in the lumen
What is inflammatory diarrhoea?
Damage to the intestinal mucosal cell so that there is a loss of fluid and blood
In addition, there is defective absorption of fluid and electrolytes
What can cause osmotic diarrhoea?
- Non-absorbable substance
- Malabsorption so that high concentrations of solute remain in the lumen
- Specific absorptive defect - coeliac disease
How can you distinguish between osmotic diarrhoea and other types of diarrhoea?
- Remove the malabsorptive substance
- Bloating?
What are the causes of inflammatory diarrhoea?
- Infection (Shigella)
- Inflammatory conditions (UC, Crohn’s)
What is the reservoirs of E. Coli O157?
Cattle
What can cause diarrhoea due to abnormal motility?
- Diabetic (arse)
- Post-vagotomy
- Thyrotoxicosis
What are the clinical features of Salmonella infection?
- Diarrhoea
- Vomiting
- Fever
- Septicaemia
What is Haemolytic Uraemic Syndrome (HUS)?
Shiga-Like Toxin (SLT) binds to globotriaosylceramide -> platelet activation stimulated -> microangiopathy
Platelets bind to endothelial, glomerular, tubular and mesangial cells
What type of E. Coli causes Enterohaemorrhagic E. Coli infection?
E. Coli O157:H7
What are the clinical features of E. Coli O157?
Frequent Bloody Stools