Diarrhoea Flashcards
definition of diarrhoea
more than 200g per day
loose consistency
frequency increased
Acute vs Chronic diarrhoea causes
Acute - baceterial (ecoli, campylobacter), virus (norovirus), parasitic
Chronic - many different causes, can be grouped into mechanism (inflmatory, osmotic, secretory, fatty)
How does campylobacter, giardia and enterotoxigenic e.coli cause diahorrea by different mechanisms
Campylobacter - INFLAMMATORY - causes mucosal inflammation - exudate released
Giardia - OSMOTIC - mild villous damage, which leads to malabsorption of carb and then this draws fluid in
E coli - SECRETORY - toxin stimulates excess fluid secretion
Inflammatory, osmotic, secretory, fatty diahorrea
Inflammatory - damaged epithelium, releases exudate
Osmotic - osmotically active compounds draw fluid into lumen (e.g damage to villous, malabsorption, more solutes in lumen)
Secretory - stimulation of excessive fluid secretion
Fatty - fat malabsorption (damage to cells producing enzymes)
Chronic diahorrea - Inflammatory - causes
Causes
- Inflammatory bowel disease
- diverticiulitis (inflamed pouches in bowel)
- small intestinal bacterial overgrowth - bacteria causes direct inflammation of tnereocytes
- radiation colitus
- ischameic coloitis
- colon cancer
Chronic Diahorrea - osmotic diarrhoea - causes
Carb malabsorption - lactose intolerance, irritable bowel syndrome
Coeliac disease - villous abnormality
Small intestinal bacterial overgrowth - malabsorpion of proteins, carbs, fat ad other osmoticaly acitve byproducts - attracts fluid into lumen
Laxative abuse
Chronic Diahorrea - Secretory diarrhoea - causes
Terminal ileal resection - bile acid malabsorption - surgery, bile acids enter colon and get damage
Cholecystectomy - bile flow continuous into small intestine
Microscopic colitis
Diverticulitis
Neruoedncorine tumours - rare - hormones that can drive water secretion
Small intestinal bacterial overgrowth - unabsorbed food products and bile acids can stimulate secretory cells in the colon
Disordered motlity - irritable bowel syndrome, post vagotomy diarrhoea, diabeteic aunomic neuropathy, hyperthyrodisim
Colon cancer
Laxative abuse
Chronic Diahorrea - Fatty diarrhoea - causes
Pancreatic exocrine insufficiencey - inadequate pancreatic enzymes
Bile acid malabsorption - inadequate amounts of bile acids
Small intestinal bacterial overgrowht - deconjugation of bile acids, impared micelle formation - impaired fat digestion and absorpiton
Coeliac disease - muscosal disease
Short bowel syndrome - not enough mucosal surface
Small intestinal bacterial overgrowth causes, symptoms
What - Excessive bacteria in small intestine
Symptoms - bloating, flatulence, abdominal discomfort, diarrhoea, steatorrhoea, malabsoprtion
Cause - imparied motility (migrating motor complex prevents clearning) - diabetes
Anatomic disorders - blockage of SI - stricutures, blind loops, diverticula
-metabolic, immune
SIBO mechanisms
Maldigestion - bacteria deconjugates bile acids leading to impared micellular formation and fat digestion
- Bacterial degradation of carbs in intestinal lumen, which also produces asmotically active byproduts
- bacterial degreation of bacteria precursos in lumen
- damages enterocytes by direct adherence, prodcuing enterotoxins and enzymes
What is malabsorbed with SIBO
-bile, fats, protein, vit b12 - bacteria competes for this, carbs
what types of Diahorrea in SIBO
Fatty diarrhoea - deconjugation of bile acids - impaired micelle formation, impaired fat digestion and absorption
Inflammatory - direct inflammation to enterocytes due to damage
Osmotic dihorrea - malabroption of proteins, carbs, fats and other osmotically active byproducts by bacterial metabolsim, deconjucated bile acids inhibit carb transporters
Secretory - unabsorbed food products and bile acids sitmulate secretory cells in colon
Melena - associated with
bleeding form upper GI tract
Delayed vomiting after eating suggests
Could be a pyloric obstruction
What can be done for ulcer, fibrosis/scaring with melena to treat ? delayed vomiting
endoscopic ballon dilation - to open where there is a stricture or damage, but also need to treat ulcer
can do vagotomy
what happens with rapid gastric emptying of digested food particles
high osmotic load into small intestnine, which draws large colume of fluid into jejunum
-OSMOTIC diarrhoea
What can a vasectomy lead to
- rapid entering of contents into stomach - depending on where
- increased small bowel motlitiy - can reduce this with drugs such as loperamide
what is an ileostomy
small intestine close to skin, and contains a bag to empty fluid into
Crohns disease
inflammatory - can occur anywhere on colon, causes fibrosus which can lead to strictures - skinnier areas
what could happen with terminal ilium removal?
-how to treat?
could get reduced reuptake of bile salts via enterohepatic circulation
- fat malabsoption - steatorrhoea
- bile salts in colon - stimulate water and electrolyte secretion i.e secretory diarrhoea
- more irritating - secretory
- more fatty - steatorrhoea
- can treat with cholestryamine - drug that binds bile
Short bowel syndrome
- what will be malabsrobed
- what are adaptive processes
- management
small bowel surgery
- malabsorption of vit, min, water, electrolytes, proteins, fats, carbs, bile
- if have colon and iliocacel valve then do better - colon resorbs water and iliocacel valve can slwo down transit to colon
Adaptive process - villiu hypertorphy
-colon increases absorpative capacity
Management - dietary - low osmotic load -anti-motlility drugs -acid suppressant medications cholestryamine total parenternal nutrtion
