Diarrhoea Flashcards
How do patients commonly present in the context of diarrhoea?
irregular bowel habits
Change in bowel habits
What are the red flag signs for cancer in someone presenting with diarrhoea?
- Change in bowel habit
- Bleeding
- Unintentional weight loss
- Family history of bowel or ovarian cancer
- > 50 years
- Symptoms lasting >6 weeks
- Anaemia
- Abdominal or rectal mass
What should you do if a patient presents with red flag cancer symptoms?
Refer 2ww cancer pathway
What are the 2 main definitions of diarrhoea?
> 200g stool / 24h
3+ stool/ day and loose
What is the definition of acute and chronic diarrhoea?
Acute= < 2 weeks
Chronic= >4 weeks
List the common causes of acute diarrhoea and how long each takes to present?
Dietary indiscretion (few hours)
• Viral infection (24-48 hours)
• ‘Food poisoning’
• Travellers’ diarrhoea (2-5 days)
When is oral rehydration therapy used in acute diarrhea?
When it is sever
Which viruses causes acute diarrhoea?
Rota virus
Adenovirus
Norovirus
SRSV
Which parasites causes acute diarrhoea?
G. intestinalis C. parvum Microsporidium I. Belli Cyclospora E.histolytica
Which bacteria causes acute diarrhoea?
Shigella Salmonella Campylobacter Enterohemorrhagic Escherichia coli Enteroinvasive Escherichia coli V.Cholerae
Which 2 bacteria are the most common cause of acute diarrhoea and where are they found?
Salmonella
Campylobacter
Found in poultry, eggs and milk
How is acute diarrhoea treated?
First line-
Observation
Oral rehydration therapy
If its sever-
IV fluids/ antibiotics
What is the composition of the oral rehydration therapy used for diarrhoea?
1L water 3.5g sodium chloride 2.5g sodium bicarbonate 1.5g potassium chloride 20g glucose
Under which circumstances would a patient be treated with IV fluids and antibiotics?
If condition gets worse Elderly or immunocompromised Frequent bloody stools Severe abdominal pain Temp > 38.5 oc Hypovolaemia
What are the causes of steatorrhea (fatty diarrhoea)?
Gastric causes
Post-gastrectomy (dumping syndrome)
Small bowel causes
Coeliac disease
Crohn’s disease
Small bowel resection
Pancreatic causes (loss of digestive enzymes)
Chronic pancreatitis
Pancreatic cancer
Cystic fibrosis
Hepatobiliary pathway causes
Primary biliary cirrhosis
Ileal resection (failure of bile acid absorption at the terminal ileum)
How is Pancreatic insufficiency diagnosed and which imaging tests can be run?
Normal red cell folate
Stool assessment-
• Faecal fat > 20g / 24h (N <7g)
• Faecal elastase
imaging
• Plain abdominal radiograph / US
• Abdominal CT, EUS, MRI, MRCP
ERCP
How is small intestinal disease diagnosed and which imaging tests can be run?
- Low red cell folate
- Anti - TTG antibodies
- Duodenal / jejunal/ TI biopsy
- Small bowel imaging – CT, MRE
When taking someone’s history on diarrhoea, which systemic medical conditions should you ask about which could cause diarrhoea?
diabetes, thyrotoxicosis, systemic sclerosis
In assessing someone’s family history in those with chronic diarrhoea which conditions should you ask about?
IBD, malignancy, coeliac
Which medications should you ask about in someone with diarrhoea?
NSAIDS
Antibiotics
PPI’s
Laxatives
If someone as rapid onset symptoms of diarrhoea (<6h), which infective causes should you be considering?
Toxin-producing organism (B. cereus, S. aureus)
If someone has fever and diarrhoea, which infective causes should you be considering?
- Invasive bacteria (Salmonella, Shigella, Campylobacter)
- Enteric viruses
- Cytotoxic organism (C. difficile, E. histolytica)
If someone has bloody stool and diarrhoea, which infective causes should you be considering?
Invasive bacteria (Salmonella, Shigella, Campylobacter, E.coli) - Amoebic dysentery (travel history)
If someone develops diarrhoea after taking antibiotics which infective cause should be considered?
C difficile
Which 8 drugs can cause chronic diarrhoea?
Alcohol Antibiotics Anti-depressants (lithium, SSRIs) Anti-hypertensives Cholesterol lowering agents GI drugs (Mg++, H2RA, PG analogs, 5-ASA) NSAIDs Oral hypoglycemics (biguanides)
Which conditions in a patients medical history should be asked about when they present with chronic diarrhoea?
pancreatic disease or abdominal surgery
What is the cause of osmotic diarrhoea?
nonabsorbable substance
- high concentration of solute in malabsorption
- specific defect eg: disaccharidase deficiency
What is the cause of secretory diarrhoea?
inflammation eg: IBD
- infection eg: salmonella
- enterotoxins from eg: E. coli, V. cholera
- hormones eg: neuroendocrine tumours
- bile salts and fatty acids
What is the cause of motility related diarrhoea?
thyrotoxicosis, IBS, DM autonomic neuropathy
How is mild, moderate, sever, complicated, and life threatening C. difficile infections categorised?
Mild: 3 tools (Bristol Stool Char 5-7)
Normal WCC
Moderate: 3-5 stools per day Raised WCC (<20 x10(9)/l)
Sever- WCC > 20 x10(9)/l, T > 38.5 oC, > Cr
Abdo pain or XR acute colitis
Complicated: Hypotension, partial ileus (lack of movement some where in the intestines)
Evidence of severe disease on CT
Life threatening: Complete ileus or Toxic megacolon
How is mild, moderate, sever, complicated, and life threatening C. difficile infections treated?
Mild: Oral metronidazole Moderate: Oral metronidazole Sever: oral vancomycin Complicated: Oral vancomycin + iv metronidazole Life threatening: Oral vancomycin + iv metronidazole Faecal microbiota transplant Consider colectomy
When a patient comes in with diarrhoea, which blood test should you order?
Blood tests- - FBC - anaemia - Inflammatory markers wcc, platelets, CRP, - U&E - dehydration/ AKI - Albumin/Ca/P - nutritional status - Haematinics - TTG antibodies and IgA - TFTs
When a patient comes in with diarrhoea, which stool and other test should you order? (not blood tests)
- Stool weight
- MC&S, CDT, cysts, ova, parasites
- Faecal calprotectin- IBD- indicates the migration of neutrophils to the intestinal mucosa
- FIT (faecal immunochemical test for Hb) (guides referrals for those with suspected colorectal cancer without rectal bleedingblood in stool is not always visible so this test helps in identifying it)
- Faecal alpha-1-antitrypsin (Fecal clearance of plasma alpha-1-antitrypsin is used as a measure of protein leakage into the intestinal tract)
- Stool pH/ electrolytes/ reducing substances
- BMI and nutritional status
When a patient comes in with diarrhoea, which investigations should be order? (not blood tests or stool tests)
Colonoscopy and biopsies
others if required-
• Duodenal biopsy- Gold standard for coeliac disease
• Small bowel MRI- (IBD, inflammation, bleeding sources, vascular abnormalities, tumours)
• Video-capsule endoscopy- used to search for a cause of bleeding in small intestines e.g. polyps, IBD, ulcers, tumours
• Cross-sectional imaging- done with contrast if fistula is suspected, IBD and proximal small bowel activity assessments