CSI 16 Flashcards
In inflammatory diarrhoea what is found in the stool?
Faecal leukocytes
Occult blood
In non inflammatory diarrhoea what does the stool look like?
Watery and large in volume
How frequent is stool in non inflammatory diarrhoea?
Over 10-20 times a day
What is not found in stool in non inflammatory dairrhoea?
No tenesmus, blood in the stool, fever or faecal leukocytes
What size is the stool in secretory diarrhoea?
Larger
What size is the stool in osmotic diarrhoea?
Smaller
How does fasting affect secretory diarrhoea?
Doesn’t improve it
How does fasting affect osmotic diarrhoea?
Improves it
What are the 2 types of inflammatory diarrhoea?
Non infectious and infectious
What are the 2 types of non inflammatory diarrhoea?
Secretory and osmotic
What are the 2 types of osmotic diarrhoea?
Maldigestion and malabsorption
What are the main symptoms of inflammatory dairrhoea?
Mucoid and blood stool
Tenesmus
Fever
What is tenesmus?
Cramping rectal pain
What are the 3 classes of diarrhoea and what time periods distinguish them?
Acute (<14 days)
Persistent (>14 days)
Chronic (> 4 weeks)
What type of cause is IBS for diarrhoea? What does this mean?
Its a functional cause meaning symptoms are present but there is no structural change causing them
What is the cause of diarrhoea called if its a result of a structural change?
Organic cause
How much fluid enters the body everyday? From where?
1-2L from diet
6-7L from body secretions
How much fluid is excreted everyday?
0.1L
How much fluid is reabsorbed everyday?
Up to almost 9L (99% of what enters the body)
What are the 2 cells types involved in diarrhoea and how do they contribute to its cause?
Enterocytes- these absorb solutes etc so lack of this can cause diarrhoea as lack of solute absorption means osmolarity in enterocytes is low so water doesnt enter
Lumen cells- there can be fluid retention here if osmolarity is high due to high levels of solute
Whats the pathophysiology behind inflammatory diarrhoea?
The epithelium is destroyed due to inflammation that arises after infection so absorption is not possible via enterocytes
Whats the pathophysiology behind secretory diarrhoea?
There is altered ion transport across the mucosa, solutes remain in the lumen increasing osmolarity so water is not reabsorbed
Whats the pathophysiology behind malabsorption causing diarrhoea?
Food is digested but it contains components that cannot be absorbed, solutes and water are therefore held in the lumen
Whats the pathophysiology behind maldigestion causing diarrhoea?
Food is undigested due to things such as enzyme deficiency, nutrients therefore cannot be absorbed if they aren’t broken down and so solutes and water are held in the lumen
What is the general treatment for inflammatory diarrhoea?
Anti inflammatories
Antibiotics/virals for infections
Oral rehydration
What is the general treatment for secretory diarrhoea?
Block channels that allow movement from enterocyte to lumen
Activate channels that allow movement from lumen to enterocyte
What is the general treatment for malabsorption causing diarrhoea?
Depends on the nature of malabsorption but options include
Avoid foods you cant absorb
Increase absorption via channels
Steroids
What is the general treatment for maladigestion causing diarrhoea?
Enzyme replacement
Why is oral rehydration therapy so important?
The main reason diarrhoea kills is because of dehydration and massive solute loss, rehydration therapy helps with this
How does oral rehydration therapy work?
Giving one part sodium to 2 parts water allows sodium to move into enterocytes so water potential falls and reabsorption into enterocytes can begin again
What is the main difference between IBD and IBS?
IBD is an organic disorder
IBS is a functional disorder
(cause is identifiable as a structural change vs not)
What symptoms are specific to IBS?
Alternating constipation and diarrhoea
Mucus in stool
Bloating
What symptoms are specific to IBD?
Weight loss
Fever
Blood in stool
Anaemia
What symptoms occur in both IBD and IBS?
Abdominal pain
Fatigue
Faecal urgency
What are gastrology investigations one can do when trying to diagnose someone?
FBC Urea and electrolytes CRP Liver function tests Colonoscopy Barium contrast ESR Stool sample Faecal occult blood test Antibody assay
What is FBC useful for in relation to gastro?
To look for anaemia and inflammation
What is a urea/electrolyte test useful for in relation to gastro?
To check renal function and electrolyte status
What is CRP useful for in relation to gastro?
Marker of infection or inflammation
What is colonoscopy useful for in relation to gastro?
Checking for cancer or coeliac disease
What is a stool sample useful for in relation to gastro?
Check for bacteria and infection
What is a faecal occult blood best useful for in relation to gastro?
For checking if there is non visible blood present in the stool
When is faecal occult blood test used in gastro?
If there is no blood visible present, in older patients, when IBD or colorectal cancer may be suspected
What is antibody assay useful in relation to gastro?
When screening for coeliac disease
When is faecal calproctectin raised?
In IBD, coeliac or colon cancer
Is faecal calproctectin specific or non specific?
Non specific, it doesn’t tell you the exact cause
What is faecal calproctectin?
A surrogate marker of inflammation in the bowel
What pathophysiology underlies raised faecal calproctectin?
Neutrophils moving into the bowel
How is Crohn’s disease characteristically described?
Non continuous, granulomatous, deep inflammation
What are granulomas?
Aggregations of neutrophils
Where in the GI tract is affected by Crohn’s?
Anywhere from the mouth to the anus
Where in the GI tract is affected by UC?
Starts at the rectum and extends upwards continuously but doesn’t extend past the large bowel (may rarely invade ileum)
What happens to the no of goblet cells in Crohn’s?
Increases
When doe Crohn’s present?
Often in children but can also present in teenage years and as an adult without any childhood history too
How is appearance of the tract commonly described in Crohn’s?
Cobblestone appearance
How is appearance of the tract commonly described in UC?
Pseudo polyps
What causes pseudo polyps to arise in UC?
Cycle of inflammation and scarring
What is seen in histology in Crohn’s?
Granulomas
What is seen in histology in UC?
Crypts abcesses
What layers of the gut does UC affect? Whats the clinical significance of this?
Confined to mucosa and submucosa, this increases risk of colorectal cancer
What layers of the gut does Crohn’s affect? Whats the clinical significance of this?
Transmural- it can affect all layers of the bowel (mucosa, submucosa, muscularis and serosa), this means fistulas can form
What are fistulas?
Abnormal connections from a hollow tube to somewhere else
What does the conservatory management of Crohn’s involve?
Stop smoking
Dietary advice
Psychological help eg support groups
How is an acute flare up of Crohn’s treated?
Corticosteroids but only short term to induce remission
How is Crohn’s treated medically long term?
Azothiopine and biologics
Why may surgery be needed in Crohn’s?
Due to risk of strictures or fistulas but they should be left as late as possible as chance of needing more surgery will only increase
What pharmacological medicines can make Crohn’s worse?
Anti inflammatories like ibuprofen
Medicines to relieve stomach cramps or diarrhoea eg loperamide
What vaccinations are recommended for those with Crohn’s and why?
The flu jab every year and the once off pneumococcal vaccine
What vaccinations are not recommended for those with Crohn’s and why?
Live vaccines eg MMR as they could make you more ill
How is pregnancy affected by Crohn’s?
It isn’t much but women should tell their GP if they are planning to get pregnant or if they get accidentally get pregnant as some Crohn’s medications can harm the baby
How is female fertility affected by Crohn’s?
It shouldn’t be much but it might be harder to get pregnant during a flare up
How is male fertility affected by Crohn’s?
Some medications can temporarily reduce fertility in men
How is contraception affected by Crohn’s?
Some types might not work as well eg the pill
Why might malnutrition arise in Crohn’s?
There is difficulty absorbing nutrients from food and people might be put off food because of diarrhoea and other symptoms, this can lead to osteoporosis and iron deficiency anaemia
What is the relationship between bowel cancer and Crohn’s? How is this managed
Risk increases in those with Crohn’s
Risk is low at first and increases the longer you have the condition
This is managed by screening for cancer regularly if the patient has had Crohn’s for more than 10 years via colonoscopies
