Diahorrea Flashcards
How does the patient present?
Terrible diarrhoea 6 weeks but it has gotten much worse Tummy pain Could not wait to see GP 3-4 a day for a month 8x recently Bad overnight Liquid, brown, sometimes blood from wiping Sample all clear from GP Weight loss - 7kg Tired - no energy Adopted Smokes 5 a day
How does she describe the pain?
Comes and goes
Left side
No change after opening bowels
How can diarrhoea be defined?
Three or more loose or liquid stools per 24 hours, and/or
Stools that are more frequent than what is normal for the individual lasting <14 days, and/or
Stool weight greater than 200 g/day.
How can diarrhoea be classified?
Acute (≤14 days)
Persistent (>14 days), or
Chronic (>4 weeks)
Describe the basic pathophysiology of diarrhoea?
10L of fluid enters GI tract daily
Small intestine responsible for reabsorbing (99%)
0.1L excreted in faeces
In diarrhoea there is decreased reabsorption or increased secretion
Or increase in bowel motility
From where is fluid secreted into the GI tract?
Food Drink Salivary glands Stomach Pancreas Bile ducts Duodenum
What are the two types of diarrhoea?
Inflammatory
Non-inflammatory
What can cause inflammatory diarrhoea?
Material
Viral
Parasitic
Or early bowel ischaemia, radiation injury or IBD
What are the associated symptoms of inflammatory diarrhoea?
Mucoid and bloody stool
Tenesmus
Fever
Severe crampy abdominal pain
What are the main features of the diarrhoea in inflammatory diarrhoea?
Small in volume
Frequent bowel movements
What are the most common causes of inflammatory diarrhoea?
Campylobacter, Salmonella, Shigella, Escherichia coli, or Clostridium difficile
In who is virus related diarrhoea common in?
Children who attend day care centres
What are the most common causes of acute diarrhoea in developing countries?
Protozoa and Parasites
What findings might be found in inflammatory diarrhoea?
Examination of the stool may show leukocytes, and tests for faecal occult blood may be positive.
The test for faecal leukocytes is plagued by a high rate of false-negative results leading to low sensitivity, but a positive test is very informative.
What are the main features of non-inflammatory diarrhoea?
watery, large-volume, frequent stool (>10 to 20 per day).
Volume depletion is possible due to high volume and frequency of bowel movements.
There is no tenesmus, blood in the stool, fever, or faecal leukocytes.
Histologically the GI architecture is preserved.
What can non-inflammatory diarrhoea be further divided into?
Secretory
Osmotic
What happens in secretory diarrhoea?
Altered transport of ions across the mucosa
which results in increased secretion and decreased absorption of fluids and electrolytes from the GI tract
especially in the small intestine
What causes secretory diarrhoea?
Enterotoxins Hormonal agents Laxative use Intestinal resection Bile salts and fatty acids
Where can enterotoxins be from?
Vibrio cholerae,
Staphylococcus aureus
enterotoxigenic E coli
and possibly HIV and rotavirus.
What hormonal agents can cause secretory diarrhoea?
Vaso-active intestinal peptide
Small-cell cancer of the lung
Neuroblastoma
What conditions can secretory diarrhoea be seen in?
Coeliac sprue
Collagenous colitis Hyperthyroidism
Carcinoid tumours
What are the features of osmotic diarrhoea?
Smaller stool volume
Improves or stops with fasting
What does osmotic diarrhoea result from?
presence of unabsorbed or poorly absorbed solute (magnesium, sorbitol, and mannitol)
in the intestinal tract
that causes an increased secretion of liquids into the gut lumen
What tests are done with osmotic diarrhoea?
Measuring stool electrolytes shows an increased osmotic gap (>50), but the test has very limited practical value. Stool (normal or diarrhoea) is always isosmotic (260 to 290 mOsml/L).
What can osmotic diarrhoea be subdivided to?
Maldigestion
Malabsorption
What does maldigestion refer to?
Impaired digestion of nutrients within the intestinal lumen or at the brush border membrane of mucosal epithelial cells.
It can be seen in pancreatic exocrine insufficiency and lactase deficiency
What does malabsorption refer to?
Impaired absorption of nutrients.
It can be seen in small bowel bacterial overgrowth, in mesenteric ischaemia, post bowel resection (short bowel syndrome), and in mucosal disease (coeliac disease)
How much fluid is secreted into GI tract?
6-7 litres
How much fluid is lost in faeces?
0.1L
What happens to the fluid that is not excreted?
Gets absorbed via the walls of the small and large intestine
Why does fluid enter enterocytes?
There are lots of solutes in enterocytes
What happens in inflammatory diarrhoea (enterocytes)?
Destruction of the epithelium due to inflammation
Enterocytes cannot absorb fluids
Excess fluid in lumen
What happens in secretory diarrhoea (enterocytes)?
Ion channels become wrongly activated so solutes moves into the lumen
E.g. Cholera - chloride channel on enterocyte membrane becomes activates
Fluid follows the chloride
What happens in maldigestion diarrhoea (enterocytes)?
Solutes are not able to digest
Products remain in lumen - high solute concentration
Fluid moves to lumen
E.g. lactose intolerance
What happens in malabsorption diarrhoea (enterocytes)?
Solutes not absorbed by enterocytes
E.g. prunes
Sorbitol is not absorbed by enterocytes
Water is retained
What drug could help inflammatory?
Anti-cytokines e.g. Anti-TNF
What drug could help secretory?
Block dysregulated channel
What drug could help maldigestion?
Enzyme replacement to facilitate reabsorption
What do you acutely want to do for all types of diarrhoea?
Rehydration
e.g. Oral rehydration solution
How does ORS work?
SGLT-1 = sodium glucose linked transporter
Give 1 glucose and 2 sodium takes both in
Pump into enterocytes
Why does diarrhoea kill?
Dehydration
ORS essential especially in children
What is chronic diarrhoea?
Symptoms for more than 6 weeks
What is IBS?
Functional cause of diarrhoea
No known structural changes
Symptoms are unexplained
Non-progressive and will not kill patient
What are the symptoms of IBS?
Tiredness Stomach pain Bloating Diarrhoea Constipation Mucus in stool
What are the symptoms of IBD?
Abdominal pain
Diarrhoea
Fatigue
Weight loss
Fever
Blood in stool
What are some organic causes of diarrhoea?
IBD
Coeliac
Bowel Cancer
Organic = we can find a cause
What are the two types of blood in stool?
Blood on toilet paper
Blood mixed in stool
What was found on the patients abdo exam?
Soft abdomen
Tenderness particulary in LLQ
No masses
What investigations does the A&E doctor want to conduct?
FBC - anaemia and signs of inflammation
U+E’s - check renal function and electrolyte status
CRP- look for infection/inflammation
What further investigation should be conducted?
Faecal Occult Blood Stool antigen Faecal calprotectin Colonoscopy LFTs
What further bloods should be conducted?
LFTs - includes albumin level which if low can indicate acute inflammation or malnutrition
Thyroid function tests
Ferritin, B12 and Folate
Antibody assay for coeliac disease
What stool tests should be conducted?
Eggs + Cysts (associated with parasites) shed intermittently in the stool
3 separate stool samples, 2 days apart
Faecal calprotectin
What stool tests should be conducted?
Eggs + Cysts (associated with parasites) shed intermittently in the stool
3 separate stool samples, 2 days apart
Faecal calprotectin - indicated migration of neutrophils into intestinal mucosa
Non-specific but looks for evidence of inflammation
What are the patients results?
Raised CRP
Raised WBC
Elevated faecal calprotectin
Now, what are the top differentials?
IBD
Colon Cancer
What does the A&E doctor do?
Refer to Gastroenterologist
What does the specialist do?
Conduct colonoscopy
What were the colonoscopic findings?
Non continuous areas of linear ulcers with cobblestone appearance are seen extending from the caecum through to the splenic flexure.
When examined under a microscope, changes are seen in the mucosa, submucosa and muscularis propria.
Numerous non caseating granulomas and increased goblet cells noted.
What is Ms Allen’s diagnosis?
Crohn’s disease
What tells us it is Crohn’s disease?
Non- continuous Cobbelstone appearance Caecum to splenic flexure Granulomas - collection of neutrophils Changes to mucosa, submucosa, muscularis and serosa (transmural changes)
What would ulcerative collitis look like on a colonscopy?
Continuous areas of inflammation Starts at rectum and continues Does not extend beyond large bowel (illeum potentially in severe disease) Crypt processes Affects only mucosa and submucosa
What are some complications of Crohn’s?
Can get a whole (fistula) forming due to transmural involvement
What are some complications of UC?
High predisposition to Colon Cancer
What treatments can be used for Crohn’s? (conservative)
Stopping smoking - referral to cessation clinic
Exercise
Dietary advice to prevent malnourishment
Psychological support - groups
What treatments can be used for Crohn’s? (medical)
Corticosteroids to induce remission
Azothiprine or bilogica (Mabs) long term to dampen down immune system
What treatments can be used for Crohn’s? (surgical)
Bowel resection
May need ileostomy for a few months post-op
Mainly due to strictures and fistulas
Leave as late as possible due to the chance of further surgeries
When should you see a GP re crohn’s?
blood in your poo
diarrhoea for more than 7 days
frequent stomach aches or cramps
lost weight for no reason, or your child’s not growing as fast as you’d expect
What causes Crohn’s disease?
your genes – you’re more likely to get it if a close family member has it
a problem with the immune system
smoking
a previous stomach bug
an abnormal balance of gut bacteria
What are the other symptoms of Crohn’s?
a high temperature feeling and being sick joint pains sore, red eyes patches of painful, red and swollen skin – usually on the legs mouth ulcers children grow more slow than usual
What would your GP ask you about?
your symptoms
your diet
if you’ve been abroad recently – you might have an infection
any medicines you’re taking
if you have a family history of Crohn’s disease
What investigations might your GP do?
feel and examine your tummy
take a sample of blood
ask you to provide a poo (stool) sample
What investigations might a specialist do?
Colonoscopy
Biopsy
MRI/CT Scan
How can steroids help with Crohn’s?
can relieve symptoms by reducing inflammation in your digestive system – they usually start to work in a few days or weeks
are usually taken as tablets once a day – sometimes they’re given as injections
may be needed for a couple of months – do not stop taking them without getting medical advice
What are the side effects of steroids?
weight gain indigestion problems sleeping an increased risk of infections slower growth in children
What can be helpful in children and young adults?
Liquid diet
Drinks containing all the nutrients
Avoids the risk of slower growth that happens with steroids
What are the side effects of enteral nutrition?
Nausea
Diarrhoea
Constipation
What immunosuppressants might be taken with Crohn’s?
azathioprine, mercaptopurine and methotrexate
What can immunosuppressants do in Crohn’s?
can relieve symptoms if steroids on their own are not working
can be used as a long-term treatment to help stop symptoms coming back
are usually taken as a tablet once a day, but sometimes they’re given as injections
may be needed for several months or years
What are the side effects of Immunosuppressants?
feeling and being sick, increased risk of infections and liver problems
What biological medicines are used in Crohn’s?
adalimumab, infliximab, vedolizumab and ustekinumab
What can biological medicines do in Crohn’s?
can relieve symptoms if other medicines are not working
can be used as a long-term treatment to help stop symptoms coming back
are given by injection or a drip into a vein every 2 to 8 weeks
may be needed for several months or years
What are the side effects of biological medications?
increased risk of infections and a reaction to the medicine leading to itching, joint pain and a high temperature
When might surgery be recommended?
the benefits outweigh the risks or that medicines are unlikely to work
What does a resection involve?
- Making small cuts in your tummy (keyhole surgery).
- Removing a small inflamed section of bowel.
- Stitching the healthy parts of bowel together.
What might you need to careful about with Crohn’s?
Triggers
e.g. certain foods
pharmacy medicines
What’s the deal with Crohn’s and vaccinations?
Flub jab yearly
Avoid live vaccines e.g. MMR
What might be more difficult during a flare up?
Getting pregnant
What might not work as well when you have Crohn’s?
Some contraceptives
e.g. the Pill
What are possible complications of Crohn’s?
Damage to bowel e.g. scarring, narrowing, ulcers, fistulas
Difficulty absorbing nutrients - osteoporosis, iron deficiency anaemia
Bowel cancer
How does the risk of bowel cancer change with Crohn’s?
after 10 years the risk is about 1 in 50
after 20 years the risk is about 1 in 10
after 30 years the risk is about 1 in 5
What should people with Crohn’s do?
Have regular colonoscopies
