Lecture 28; Diarrhoea Flashcards
Whats important in defining diarrhoea?
- Consistency (loose)
- Frequency (increased for individual) (3+)
What is acute vs chronic defined as?
Acute up to 14 days
Chronic over 14 days
Causes are very different
What are the causes of acute diarrhoea?
Infection, infection, infection
- Bacterial
- Viral
- Parasitic
What can the causes of chronic diarrhoea be grouped into?
- Inflammatory
- Osmotic
- Secretory
- Fatty
Whats the pathophysiology of the causes of chronic diarrhoea?
Inflammatory - Damaged epithelium lead to exudate Osmotic - Osmotically active compound draws fluid in Secretory - Stimulation of excessive fluid secretion (inc. dehydr risk) Fatty - Fat malabsoprtion
What are a few points to make about diarrhoea in general?
- Some conditions have more than one underlying mechanism
- If blood (THEN MUST BE INFLAMMATORY)
- Description is usually unhelpful (except; steatorrhoea (oily) or blood))
Whats of note when it comes to acute diarrhoea infection?
Different mechanisms, can be;
- Inflammatory
- Secretory
- Osmotic
Whats an example of acute diarrhoea (inflammatory);
Campylobacter
- Inflammatory diarrhoea
- Causes mucosal inflammation -> Exudate
Whats an example of acute diarrhoea (osmotic);
Gardia
- Osmotic diarrhoea
- Mild villous atrophy -> CHO malabsorption (similar to lactose intolerance)
Whats an example of acute diarrhoea (Secretory);
E. Coli
- Secretory diarrhoea
- Toxin stimulates excessive fluid secretion
Describe the causes of chronic inflammatory diarrhoea?
- Inflammatory bowel disease
- Diverticulitis
- SI bacterial overgrowth (bacterial causes inflam of enterocytes)
- Radiation colitis
- Ischeamic colitis
- Colon cancer
What causes chronic osmotic diarrhoea?
CHO malabsorption
- Lactose intolerance
- IBS
Coeliac disease
- Villous abnormality
SI bacterial overgrowth
- Malabsoprtion of pro, CHO, fats and other osmotically active by-products
Laxative abuse
What causes chronic secretory diarrhoea?
- Terminal ilium resection (bile acid malabsorption)
- Cholecystectomy (continuous bile flow into SI)
- Microscopic colitis (lymphocytis and collagenous colitis)
- IBD
- Diverticulous
- Neuro-endocrine tumors
- SI bacterial overgrowth (unabsorbed foods, bile)
- Disordered motility
- Colon cancer
- Laxative abuse
i.e Cancer, SIBO, Inflammation, Motility, GI length/operations, Absorption
What causes chronic fatty diarrhoea?
- Pancreatic exocrine insufficiency (no enzymes)
- Bile acid malabsorption (low bile)
- SI bacterial overgrowth (impaired micelle form)
- Coeliac disease
- Short bowel syndrome (not enough mucosal surface)
What is SIBO (Small intestinal bacterial overgrowth)?
SIBO
- Excessive amounts of colonic bacteria in the SI
- Bloating, flatulence, abdo pain, diarrhoea, steatorrhoea and malabsoprtion
