Diahorrhea Flashcards
(35 cards)
How does WHO define diarrhoea?
3 or more loose or liquid stools per day
OR
more frequent passage than is normal for the individual
Faecal weight more than 200g/day
How do we distinguish chronic/acute diarrhoea?
Acute is less than 2 weeks in duration
Chronic more than 4 weeks
What should you ask about regarding diarrhoea?
Frequency Consistency Presence of blood/mucus Associated symptoms - pain - vomiting - fever BO at night? Urgency? Any incontinence? Do the stools flush away - steathorrea as a result of malabsorption typically do not
How do we classify stool?
Bristol stool chart
What are the different mechanisms of diarrhoea?
Secretory e.g. cholera Osmotic e.g. hypolactasia, drugs, malabsorption Exudative e.g. IBD Abnormal Motility e.g. IBS Mixed Overflow
What is dysentery?
Diarrhoea associated with blood
Also fever, abdominal pain and vomiting
Caused by bacteria commonly e.g. shigella, salmonella
Which amoeba can cause dysentery?
Entamoeba histolytica
Need for ‘hot’ stool sample
Straight to the lab
How do you ellicit that is a GI infection causing diarrhoea?
Short history
Precipitating event e.g. food, personal contact or travel
Fever, abdo pain and vom
What is the treatment for GI infection diarrhoea?
AB treatment and rehydration
What are the main features of C. diff diarrhoea?
Can cause pseudomembraneous colitis
Concern in healthcare settings
Associated with AB use
Can lead to sig mortality in elderly
What is the treatment for c. diff diarrhoea?
Rehydration
Oral metronidazole or vancomycin
In resistant cases - FMT
How does malabsorption cause diarrhoea?
Failure to secrete digestive enzymes - pancreatic disease
OR
Failure to absorb through gut wall - mucosal disease
What are the features of malabsorption diarrhoea?
Steatorrhoea
Pale, bulky, offensive stools
Difficult to flush
Weight loss
Lethary
Anorexia
Abdo discomfort and bloating
How do we assess malabsorption in the lab?
Stool sample for fat globules
3 day faecal fat estimation
Look at FBS for B12, Fe, Ferritin
What diseases can cause malabsorption?
Pancreatic Coeliac Crohn's Infective/Post-infective Bacterial overgrowth Biliary obstruction
What should you do if you want to know if it is pancreatic or intestinal malabsorption?
Faecal elastase
CT scan/ERCP
Trial therapy e.g. pancreatic enzymes and monitor success
Give antibodies to check for coeliac
What is tTG?
tTG Tissue Transglutaminase >90% sensitivity and specificity for coeliac disease Reduces when GF diet is adhered to Diagnostic of coeliac
What complications can arise if a GF diet is not stuck to in coeliac?
Small bowel lymphoma
Osteoporosis
What is IBD?
Chronic relapsing inflammatory disorders of the GI tract
UC and Crohn’s
UC? main features
Continuous - starts in rectum Sharp demarcation Confined to mucose M=F 25-35 years typically More common in non-smokers
Crohn’s? main features
Discontinuous (skip lesions) Can start anywhere from mouth to anus Transmural inflammation Young adults but also children and older F>M Fistulae and strictures common Granulomas in roughly 60%
What is the cause of IBD?
Complex
Disordered immune response to luminal bacteria
UC - mixed Th1 and Th2 and Th17 response
CD - Th1 and Th17 response
What are the symptoms of IBD affecting the colon?
Bleeding
Mucus
Urgency
Diarrhoea
What are the symptoms of IBD affecting the small bowel?
Abdo pain Wt. loss Lethargy Diarrhoea Abdo mass