Diarrhoea Flashcards
What is the definition of diarrhoea?
Diarrhoea is defined as 300g or more of stool per day
What are the two main categories of diarrhoea?
Inflammatory and Non-inflammatory diarrhoea
What are the symptoms of inflammatory diarrhoea?
- Fever and Pain
- Tenesmus
- Blood in the Stool
We can test the stools for faecal leukocytes, what is the problem with this test?
Faecal leukocyte test has a high false negative rate. So a negative result should be taken with a pinch of salt but a positive result is very telling
What is the typical presentation of inflammatory diarrhoea?
High volume, frequent watery stool
What is a common treatment method used for dehydration and how does it work?
Oral Rehydration Salts use a combination of glucose and sodium to stimulate the SGLT-1 transport into uptaking sodium so that water follows
How can we further divide up non-inflammatory diarrhoea?
Into osmotic and secretory. Osmotic can be further broken down into maldigestion and malabsorption
Both secretory and osmotic diarrhoea result in increased fluid in the lumen, how does the mechanism differ ?
- Secretory Diarrhoea uses molecule pumps
- Osmotic involves aquaporins allowing water to follow the solutes
How can osmotic diarrhoea be caused ?
Malabsorption or Maldigestion
What are some investigations we would do for inflammatory diarrhoea?
LFT
Faecal Calprotectin
X-Rays
What are the main conditions is IBD?
Crohn’s Disease and Ulcerative Colitis
What type of disease is IBS? How do we diagnose it ?
IBS is a functional disease. Despite very real symptoms endoscopic and microscopic evaluations appear normal. We diagnose with a diagnosis of exclusion where we rule out all other conditions.
What medications should NOT be given to someone with Crohn’s disease?
NSAIDs
Give some examples of NSAIDs.
Naproxen Ibuprofen High dose Aspirin Diclofenac Celecoxib Indomethacin
If a condition affects the small intestine which IBD condition will have caused it?
It is most likely Crohn’s which can affect anywhere from gum to bum
Where do we tend to see UC?
It always involves the rectum and normally the sigmoid and descending colon. It can theoretically however affect the entire large colon
What is the difference in the depth of gut wall they effect?
Crohn’s disease is a transmural disease meaning ulcers can span from the epithelium to the serosa. Ulcerative Colitis affects the mucosa and occasionally submucosa
What is a non-Casesting granuloma?
Caseating means cheese like and these granuloma’s (formation of immune cells) are not cheese like)
What is a pseudopolyp and is it more likely to be seen in UC or Crohn’s?
A
What is the difference in the macroscopic features of Crohn’s and UC?
A
Which disease type has flare ups and a symptomatic periods?
A
How do we treat Crohn’s?
- Acute flare ups we use corticosteroids
- Chronically we use Azothioprine, Biologics or rarely surgery (usually just to fix fistula’s and strictures)
Smoking is a common risk factor for many diseases how does it affect Crohn’s and UC?
Smoking may have a protective benefit in UC bit is harmful in Crohn’s
In terms of time period how can we define diarrhoea?
Acute: <2 weeks
Persistent: 2-4 weeks
Chronic: >4 weeks
How does the liver respond to inflammatory diarrhoea?
A
What are some symptoms that are specific to IBS when compared to IBD?
- Alternating Constipation and Diarrhoea
- Bloating
- Mucous in the stools is associated with IBS more than IBD
Strictures and fistula’s are complications of which condition in IBD ?
Crohn’s Disease
What is faecal calprotectin a marker of?
A
What is the faecal osmolar gap?
We calculate it by doing 290- 2(Na + K)
This is different to faecal osmolality which is 290, same as the plasma
How does diarrhoea affect the faecal osmolar gap?
HINT: think about different types
A
