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
