CSI 16- Diarrhoea Flashcards
Define diarrhoea?
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.
Based on duration how can you further classify diarrhoea ?
Acute (less than 14 days)
Persistent (more than 14 days), or
Chronic (more than 4 weeks).
How much fluid do we reabsorbe each day and how does diarrhoea affec this?
10 L of fluid
Mostly reabsorbed at small bowel.
overall (in both small and large bowel) 99% of fluid is reabsorbed leaving 0.1 L in feaces
Diarhheoa interferes with this process which can result in :
- Decreased absorption of fluid or
- Increased secretion of fluid and electrolytes or
- increase in bowel motility
what are the origins of the 10L of fluid entering the GI tract everyday
salivary glands, stomach, pancreas, bile ducts, and duodenum
Extensiviely classify diarrheoa
Inflammatory - can be infectious or non infectious
Non-inflammatory
- Secretory or
- Osmotic
- Mal digestion
- Mal absorption
what is inflammatory diarrhoea? what causes it and what are the symptoms nornmally associated with it
Inflammatory process going on it could be due to :
- bacterial, viral or parasitic infection or develop early in the course of bowel ischeamia/ radiation injury/ IBD
Associated symptoms are:
- Mucoid and bloody stool
- Tenesmus (feeling like you need to pass stool)
- fever
- severe crampy abdominal pain
What are the features of infectious inflammatoruy diarrhoea
Small in volume with freqent bowel movements
Does NOT reuslt in volume depletion in adults but maybe for kids or older people
what are the causes of infectious inflammatory diarrheoa?
Bacterial infections like:
- Campylobacter
- Salmonella
- Shigella
- Escherichia coli
- C.difficile
Virus more common in kids who go to day care
Protozoa and parasites - common casuse of acute diarrheoa in developing countries
what are the examination results for inflammatory diarrhoea?
what should you be wary of?
what will the histology of GI tract show?
Stool culture- show leukocytes
Feacel occult blood may be postiive.
Feacal occult has a high chance to be false negative (low sensitivity) but positive is very informative.
Histology is abnormal
what are the features of non-inflammatory diarhoea?
Very large volume, watery stool
Frequent stool like between 10 and 20 a day
Volume depletion very possible
NO tenesmus, blood in stool, fever or feacal leukocytes
Histology of GI tract is preserved
what are the features of secretory diarhhoea and what causes it?
Due to altered transport across mucosa leading to increased secretion and decreased absorption of fluids and electrolytes from the GI tract (small bowel mainly)
Not improved by fasting
Causes could be :
- enterotoxins
- Hormonal agents
- Laxative use
- intestinal resection
- bile salts
- fatty acids
The causes of secretory diarrhoea are enterotoxins and hormonal agents.
what are the sources of these causes
Enterotoxins - infection from:
- Vibrio cholerae
- S.aureus
- enterotoxigenic E.coli
- Possibly HIV and rotavirus
Hormonal agents :
- VIP
- small- cell lung cancer
- neuroblastoma
what other conditions would you see secretory diarrheoa
chronic diarrhoea with coeliac disease
collagenous colitis
hyperthyroidism
carcinoid tumours
what are the features of osmotic diarrhoea?
Stool volume lower than secretory diarrhoea
DIarhhoea improves or stops with fasting
Results from presence of unabsorbed or poorly absorbed solutes like Mg, sorbitol and mannitol. This leads to in increased secretion of fluids into GI tract
Stool electrolyte shows increased osmotic gap of more than 50 but the test isn’t very useful
Stool whether normal or diarrheoa is always isosmotic (260-290 mOsm/L)
what are the fesatures and causes of maldigestion (osmotic diraahoea)
refers to impaired digestion of nutrients within the intestinal lumen or at the brush border membrane of mucosal epithelial cells.
can be seen in:
- pancreatic exocrine insufficiency
- lactase deficiency
what are the features and casues of Malabsorption (osmotic diarrhoea)
refers to impaired absorption of nutrients.
Can be seen in:
- Small bowel bacterial overgrowth
- mesenteric ischeamia
- post bowel resection (short bowel syndrome)
- mucosal disease- celiac
what are the main symptoms of Crohns disease and when does it come
The symptoms usually start in childhood or early adulthood.
The main symptoms are:
- diarrhoea
- stomach aches and cramps- often in lower right quadrant
- blood in your stool
- tiredness (fatigue)
- weight loss
The symptoms may be constant or may come and go every few weeks or months. When they come back, it’s called a flare-up
when is it a good time to see a GP? what symptoms are pre-requisite for it.
See a GP if you or your child have:
- blood in your stool
- 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.
GP will try to determine cause of symtpoms to see if it’s Crohns
what are the treatments for Crohns
No cure for it but there are other meds:
medicines to reduce inflammation in the digestive system – usually steroid tablets
medicines to stop the inflammation coming back – either tablets or injections
surgery to remove a small part of the digestive system – sometimes this may be a better treatment option than medicines.
GP, specialist nurse or doctors over see this
what are the causes of Crohns
Exact cause is unknown but several factors play a role:
- genes – you’re more likely to get it if a close family member has it
- a problem with the immune system that causes it to attack the digestive system
- smoking
- a previous stomach bug
- an abnormal balance of gut bacteria
NO PARTICULAR DIET causes it
Crohns is hard to diagnose - similar symptoms to other disease. what Diagnostic will the GP carry out
Full history
- HPC
- DHx, FHx
- Travel
Abdo exam
IXs:- blood and stool sample tested for signs of inflammation or infection
what are the other less common symptoms of Crohns
- pyrexia
- feeling and being sick
- joint pains (arthritis)
- sore, red eyes (uveitis or episcleritis)
- patches of painful, red and swollen skin – usually on the legs (pyoderma gangronosum or erythema nodosum)
- mouth ulcers.
- Kidney stones
Children with Crohn’s disease may grow more slowly than usual.
if your GP suspects crohns and refers you to a gastroenterologist ; what tests could they do?
Colonoscopy
Colonscopy with biopsyu
MRI or CT- drink a contrast to help see it
what is involved in a colonoscopy
You have list of waht to eat (junk food only)
Take laxative the day before
Sedative is given to you (remifentanil)]
Dont drive for 24 hrs after sedative
Any polyps found will be removed swiftly
After colonoscopy, you will be looked after in recovery room
How are steroids given? How does it work and give S/Es
Reduce inflammation
Take once a day as a tablet (maybe IV)
May need to be taken for couple of months but it’s usually taken during a flare-up. for acute relief
S/Es are: weight gain, indigestion, problems sleeping, an increased risk of infections and slower growth in children
what type of diet may help in Crohns and explain why.
Give S/Es
liquid diet (enteral nutrition) may help reduce symptoms for kids or young adults
it contains all nutrients you’ll need for a few weeks
Avoids risk of slower growth with steroids.
S/Es: some people may feel sick or have diarrhoea or constipation while on the diet.
what immunosuppresants may help with crohn’s disease and explain how they help.
how do you take them?
azathioprine, mercaptopurine and methotrexate.
Can releive symptoms if steroids on their own isn’t working
Can be used as long term treatment - Several months or yrs
Tabelt- once a day; sometimes (injections) IV
S/E: Nausae and vomiting, liver porblems and increased risk of infection
when are biologics used for crohn’s? what are they and how do they help.
Stronger meds given when other meds haven’t worked
e.g. adalimumab, infliximab, vedolizumab and ustekinumab.
They:
- relieve symptoms
- used as long term treatment to stop symptoms comiong back (several months or yrs)
- given by injection or drip into vein every 2 to 8 wks
- S/E are:
increased risk of infections and a reaction to the medicine leading to itching, joint pain and a high temperature
when is surgery considered for crohn’s and what are the effects
Recommedned if they think the benefits outweigh risks or that meds are unlikely to work
they can relieve symptoms and help stop them from coming back for a while but they will return eventually
what are the features of a surgical resection
it involves:
- Making small cuts in your tummy (keyhole surgery).
- Removing a small inflamed section of bowel.
- Stitching the healthy parts of bowel together.
hospital stay is a week and it takes a month to fully recover
you may need ileostomy until bowel recovers
May still need to take meds after surgery to stop symptoms coming back
Living with Crohns
what are the diet and lifestyle measures that can help you
No special. diet, kids may need liquid diet
Have a healthy balanced diet
if you think a particular food triggers symptoms, see if avoiding it helps
Do not make any big diet changes without talking to GP
Living with Crohns
what pharm meds can help you/ make it worse and explain
In some ppl, NSAIDs like Ibuprofen makes symptoms worse so avoid
Ask pharmacist or GP for advice if you’re taking a new med like loperamide
Living with Crohns
what are the vaccination measures that can help you
Biologics and immunosuprresant can increase flu risk
take flu jab every year and the one off pnuemococcal vaccines
Avoid live vaccines like MMR; make you ill
What advice should pregnant women with crohns recieve
Most ppl have normal pregnancy and healthy baby
Some meds can harm baby so
- Tell GP ASAP if you accidnetally get pregnant
- tell GP if you’re planning one- they may chnage treatment
it may be harder to get pregnant during crohns flare up but fertility should return to normla in between
Some crohns meds can temporarily reduce fertility in men
How does crohns affect contraception
Make sure you use contraception if you do not want to get pregnant.
Ask your GP or care team about the best contraception to use because some types, such as the pill, may not work as well as usual if you have Crohn’s disease.
what are the possible complications of Crohns
Increases risk of:
damage to your bowel that may require surgery – such as scarring and strictures, ulcers and fistulas
difficulty absorbing nutrients from food – this can lead to problems like osteoporosis or iron deficiency anaemia
bowel cancer – you may need regular cancer screening to check for this
what are the risks of bowel cancer after certain time passes? what will the team do?
Low at first but increases as time passes. e.g.
- after 10 years the risk is about 2%
- after 20 years the risk is about 10%
- after 30 years the risk is about 20%
if you have it for more than 10 yrs or Crohns affect multiple parts of bowel, care team may screen you (colonoscopies)
Crohn flare up are unpredictable, how can you do to get help and support to cope with it emotionally and practically
tell your friends and family about your condition – so they can understand the effect it has on your life
talk to your GP or care team – they can offer support, treatment and referral to a specialist such as a counsellor if needed
use support groups like Crohn’s and Colitis UK
Give examples and features (from f2f) of the following types of diarrhoea
Inflammatory
Secretory
Osmotic:
Inflammation- exudation of serum and destruction of epithelium. it has many causes
Swecretory- ion channels secrete excess ions into lumen. e.g. cholera enterotoxin
Osmotic (Maldigested)- lactose intolerance- cant digest lactose and hence cannot absorb it and hence there will be more wtaer in lumen
Malabsorptive- e..g substances that can’t be absorbed like prunes (Sorbitol)
what are the acute and long term treatment for diarhoea ?
Acute- Oral rehydration solution ( it gives one glucose molecule and 2 Na+ to SGLT1)- reestablished water potential needed for reabsorption to prevent dehydration/volume depletion
Long term- treat underlying cause- very relevant for IBD
Contrast the functional and organic causes of diarhoea?
Functional- IBS
- No structural change in GI tract
- No cause of symptoms we can measure
Organic:
- Can see and measure casue of symptoms
- e.g. celiac disease, cancer, IBD
Compare and contrast the symptoms of IBD and IBS.
which one does our pt have
Mucus in stool ALONE- IBS
Our pt had weight loss hence has IBD features
Explain the nuances and associated symptoms of blood in stool
Colour
- Bright red- shsows lower GI tract bleeding
- Brown- upper GI bleeding as the blood has been digested. Can present with haemetemesis also
Toilet paper (red)- problem with anus or rectum like haemorrhoids and anal fissures
if it’s mixed in stool- it could suggest cancer or IBD
what are the possible blood tests one should order if a pt comes in with diarrhoea and abdominal pain
- FBC- anaemia
- Urea & Electrolytes- check renal function and electrolyte balance
- CRP- inflammation
- LFT
- Thyroid- hyper can cause diarrhoea
- Ferrtin
- Vit B12/folate
- celiac serology for tissue transglutaminsae antibody
what possible stool test should be ordered for diarrhoea and blood in stool
Feacal occult- if blood can’t be seen visibly
Microbiology- looking for bacterial pathogens such as Cholera
Ova and cysts- (can be caused by parasite) 3 specimens 2 days apart as ova sheds intermittently
Feacal calprotectin- marker for inflammation in the bowel. Indicates migration of neutrophils to the intestinal mucosa. Inflammation could be due to cancer, celiac or IBD
what are the results of a colonoscopy and biopsy for Crohns
Non-continuous inflammation
Cobblestone appearance - due to interspersed deep ulceration
Deeper ulceration (transmural- goes through all the layers of the gut)
Non-caseating granulomas and increased goblet cells
what will the histology for crohns show
Granuloma
what are the features of UC and what will the gross pathology show?
what will colonoscopy show?
Continuous circumferential mucosa inflammation- may also affect submucosa
Always involves rectum
Gross: show pseudopolyps if UC has occurred for a long time- scarring has occurred
only affects colon- except in rare occasion affect distal ileum (UC is severe and colonic content has backwash into ileum)
what are the major complications of Crohn’s and UC
Crohns- more likely to get fistulas, ulcers and strictures
UC-
- more predisposed to colorectal cancer than Crohn’s
- Severe GI bleeding
- Fulminant colitis and Toxic megacolon (severe UC)
what does the histology for UC show?
crypt abscess are more typical for UC
what are the treatments for UC and Crohns
Lifestyle advice and conservative treatments
- Stop smoking and alcohol
- Dietary advice and refer to dietician
- Psychological support- long term (lifelong) condition.
- Acute setting:*
- Steroids are used to induce remission (short sharp way to settle it down)
- Long term:*
- Aziathoprine
- 5 ASA
- Methotrexate
- Biologics- antibodies against TNF-a like infliximab
- Surgical resection to reduce fistulas and strictures ( crohns )- last resort
what are the first line treatment for mild UC
Give rectal depositories (anti-inflammation)
Start with 5-ASA
what is the abdominal x-ray sign for structure and circumferential inflammation in ulcerative colitis?
Stricture- String sign (sting like appearance of bowel due to severe narrowing)
UC circumferential- Lead pipe sign due to loss of Haustra
