Diarrhoea Flashcards
Definition of diarrhoea
No universally agreed definition.
Abnormal passage of loose or liquid stools (types 6+7) with increased frequency (more than 3 times daily) and/ or volume of stool (more than 200g/day)
Definition of Acute diarrhoea
Lasts for less than 2 weeks
What are the features of mild dehydration?
- Lack of energy
- Anorexia
- Nausea
- Light-headedness
- Postural hypotension
What are the features if moderate dehydration?
- Apathy
- Tiredness
- Dizziness
- Muscle cramps
- Dry tongue/ sunken eyes
- Reduced skin turgor
- Postural hypotension
- Tachycardia
- Oliguria
What are the features of severe dehydration?
- Profound apathy
- Weakness
- Confusion (leading to coma)
- Shock
- Tachycardia
- Peripheral shut down
- SBP less than 90
- Anuria
How would you initially assess someone with diarrhoea?
A to E (as can cause dehydration)
Stabilise airway and breathing as required
Assess circulation
- IV access and fluids
- Bloods to send: FBC, U&Es, CRP, LFTs, TFTs, VBG and if there are signs of sepsis blood cultures
- Catheterisation if very unwell
History and Examination
What to ask in the history?
Nature of stool
- Bloody
- Mucus (IBS, colorectal cancer, polyps, IBD)
- Pus (IBD, diverticulitis, abscess)
- Watery
- Steatorrhoea
- Stool frequency
Other Sxs
- Fever
- Abdo pain
- Nausea
- Vomiting
Recent travel? (did you drink tap water/ eat anything funny?)
Contact with people with similar Sxs?
Possible sources of food poisoning?
Recent changes in medication, or use of Abx?
Immunocompromised?
SH - job not a public health risk e.g. chef
How long are viruses usually incubated for?
Around 1 day
How long are bacteria usually incubated for?
A few hours to a few days
How long are parasites usually incubated for?
Up to 2 weeks
What symptoms associated with diarrhoea may warrant admission?
- Persistent vomiting
- Painless, watery, high volume diarrhoea as this is a risk of dehydration
- Severely dehydrated, shocked or unable to retain oral fluids
What are the lower GI red flags?
- Age over 50
- Rectal bleeding
- Recent change in bowel habit
- Nocturnal Sxs
- Unexplained or unintentional weight loss
- IDA
- FH of colorectal cancer or IBD
What is important to assess for on examination?
Abdo and PR:
- Assess for masses, PR bleeding or impacted faeces
- Oral ulcers, clubbing and signs of anaemia
- Signs of dehydration (cap refill, BP, pulse, tongue/ mucous membranes, skin turgor, JVP)
What are the features of acute diarrhoea without blood?
Tends to be from the small bowel.
It is generally larger in volume and typically painless
List the causes of acute diarrhoea without blood
- Infection (gastroenteritis)
- Medications
- Hyperthyroidism
- Malabsorption
- IBS
- Crohn’s disease
- Lymphocytic colitis
- Constipation with overflow diarrhoea
What are the common pathogens that cause acute diarrhoea without bleeding?
- C diff (often follows Rx with clindamycin or broad spectrum Abx. it can cause pseudomembranous colitis)
- Cholera (Px with profuse watery diarrhoea without abdo pain or fever)
- Parasites such as giardia, entamoeba, cyclospora and cryptosporium (cause prolonged diarrhoea for more than 14 days usually without vomiting)
- Rotavirus (common in young children and is self limiting within 1 week)
- Norovirus (predominantly a vomiting illness but is accompanies with watery non-bloody diarrhoea for 1-2 days)
What medications can cause diarrhoea as a SE?
- Magnesium antacids
- NSAIDs
- PPIs
- Abx
- Metformin
- Thyroxine
What are the features of Lymphocytic colitis? (who it is associated with, clinical features and management)
Associated with medications, coeliac disease and older people
Leads to profuse non-bloody diarrhoea with a normal mucosal appearance but intraepithelial lymphocytes on biopsy
It responds well to budesonide or other systemic steroids
What are the features of acute bloody diarrhoea?
Tends to be from the large bowel
It is usually smaller in volume and painful
What are the causes of acute bloody diarrhoea?
- Infection (gastroenteritis)
- Diverticulitis
- Ischaemic colitis
- Ulcerative colitis
What are the common pathogens that cause acute bloody diarrhoea?
- Campylobacter jejuni (causes profuse watery bloody diarrhoea with fever and cramps. often a 24 hour prodromal flu-like illness)
- Salmonella (particularly serogroup D. causes bloody diarrhoea with fever and cramps that lasts from 4-7 days)
- E coli 0157 (usually causes a mild self limiting diarrhoea for less than 72 hours. VTEC E coli can lead to haemorrhagic colitis and haemolytic uraemic syndrome)
- Shigella (causes acute watery diarrhoea that may be accompanied by mucus, pus or blood for around 3 days)
- Schistomiasis
What investigations would you do for acute diarrhoea?
Bedside:
Obs
Stool cultures, foecal elastase (pancreatitis), foecal calprotectin (IBD)
Urine dip
Bloods:
FBC, U&Es (dehydration/ hypokalaemia), CRP, LFTs, TFTs, VBG, Anti-TTG (coeliac) and if there are signs of sepsis blood cultures
Imaging:
AXR (if systemically unwell to rule out toxic megacolon)
Flexi sig if high suspicion of IBD
Biopsies if indicated
What are the indications for sending a stool sample for MC&S and OCP (3 samples on 3 different days)?
- Systemically unwell
- Immunocompromised
- Diarrhoea is prolonged
- Foreign travel
- Blood/ pus in stool
What are the pathogens routinely looked for on stool sample MC&S?
- Campylobacter
- Cryptosporidium
- E. Coli
- Salmonella
- Shigella
When might there be red or white blood cells in the stool?
Particularly in Shigella and Campylobacter
How do we manage someone with acute diarrhoea?
- Treat cause
- Rehdration (oral better than IV. IV: 0.9% saline with KCl)
- Reduce gut motility (only give if clear Dx of underlying cause and avoid if infective)
- Avoid Abx (unless confirmed infection or sepsis)
What anti-motility agents can you give?
Loperamide 2mg PO after each stool - max 16mg/ day
Codeine phosphate 30mg TDS
When should anti-motility agents be avoided?
- If no cause has been found
- If cause is infectious
Give some examples of antispasmodics and when they would be given?
Given for Sx relief
Mebeverine, hyoscine butylbromide
When should advice be sought from the local health protection unit regarding the need for investigations?
- The patient is suspected public health hazard e.g. food handlers, healthcare workers, elderly residents in care home
- There is an outbreak of diarrhoea where isolating the organism may help pinpoint the source of the outbreak
- The patient is infected with certain organisms that may cause serious clinical sequelae e.g. E.Coli 0157
Is food poisoning a notifiable disease?
Yes
Why is E.Coli 0157 so important to identify?
Can cause haemolytic uraemic syndrome.
(Causes anaemia, low platelets and kidney failure)
E.Coli is most common travellers infection
What is the definition of chronic diarrhoea?
The passage of abnormally large volumes of loose stools for more than 14 days
Persistent diarrhoea is more likely infectious or non-infectious pathology?
Non-infectious
What are the differentials for chronic diarrhoea?
Colonic:
- diverticular disease
- colon cancer
- colitis (UC, Crohn’s, microscopic colitis, ischaemic colitis)
Small bowel:
- malabsorptive conditions (coeliac, bile salt malabsorption - ileal resection cholecystectomy, whipple’s disease, tropical sprue, small bowel overgrowth, chronic pancreatitis, CF
- Lactulose intolerance
- IBS
Endocrine:
- hyperthyroidism
- autonomic neuropathy from DM
- addison’s
Chronic infections:
- cryptosporidium
- giardiasis
What are the red flags for chronic diarrhoea?
- Weight loss
- Rectal bleeding
- Diarrhoea persisting more than 6 weeks in patients over 60
- FH of bowel or ovarian cancer
- Abdo or rectal mass
- Anaemia in a man or post-menopausal woman
- Raised inflammatory markers
What should you do if colorectal cancer is suspected?
Urgent 2 week wait referral
What Investigations would you do for chronic diarrhoea?
Bloods:
FBC, LFTs, TFTs, U&Es, ESR/CRP
Tests of malabsorption - calcium, B12, folate, iron studies
Antibody tests for coeliac e.g. EMA, TTG
Stool for MC&S and OC&P
also for foecal elastase, chymotrypsin and fat
Flexi sig or colonoscopy if colonic or ileal disease suspeted
