Diarrhoea Flashcards
What is the BSG definition of diarrhoea?
‘Diarrhoea is the abnormal passage of lloose or liquid stools more than three times daily and/or a volume of stool greater than 200 g/day’
What is the difference between acute and chronic diarrhoea?
•Acute diarrhoea = less than 4 weeks
Mostly: infectious and self limiting
?investigate after 1 week
•Chronic diarrhoea = more than 4 weeks
Chronic pathology
Always investigate
What are the viral, bacterial and parasitic causes of acute diarrhoea?
Viral:
- Rotavirus
- Norovirus
- Enteric adenovirus
Bacterial:
- Salmonella
- Shigella
- Campylobacter
- Staph.aureus
Parasitic:
•Cryptosporidium parvum
Which parastitic causes can cause chronic diarrhoea?
Can be chronic -
- Giardia lamblia
- Entamoeba histolytica
Name the colonic and small bowel causes of chronic diarrhoea?
Colonic:
- Ulcerative & Crohn’s colitis
- Microscopic colitis
- Colorectal cancer
Small bowel:
- Coeliac disease
- Crohn’s disease
- Bile salt malabsorption
- Lactose intolerance
- Small bowel bacterial overgrowth
Name the pancreatic and endocrine causes of chronic diarrhoea
Pancreatic:
- Chronic pancreatitis
- Pancreatic cancer
- Cystic fibrosis
Endocrine:
- Hyperthyroidism
- Diabetes
- Addison’s disease
- Hormone secreting tumours (e.g. Carcinoid, VIPoma)
What are the other causes of chronic diarrhoea?
- Drugs
- Alcohol
- Factitious (pretending to be ill)
What are the different mechanisms of diarrhoea?
- Osmotic e.g. lactose intolerance
- Steatorrhoea
- Secretory e.g.Cholera, E. Coli, gut hormones
- Inflammatory e.g. UC, Crohn’s, infections
- Neoplastic
- Ischaemic
- Post irradiation
What are the investigations for chronic diarrhoea?
•Stool tests: Microscopy & culture
Faecal elastase
Faecal calprotectin
- Blood tests: Many (e.g.FBC, CRP, TTG, TFT’s, B12 etc)
- Imaging: Colonoscopy,
CT, video capsule, MRI small bowel
(Ba enema, small bowel enema)
What does this show?
Endoscopic appearance of Ulcerative colitis
What does this show?
Endoscopic appearance of Crohn’s disease
What is ulcerative collitis?
…continuous mucosal inflammation of the colon without granulomas on biopsy, affecting the rectum and a variable extent of the colon in continuity and characterised by a relapsing and remitting course.
What is crohns disease?
…discontinuous and often granulomatous transmural inflammation affecting any area of the gastrointestinal tract.
What is the distribution of CD throughout the GI tract?
Distribution: Terminal ileum – 30%
Colonic – 30%
Ileo-colic – 30%
Other
Which is which IBD?
What are the symptoms of UC?
- Bloody diarrhoea, rectal bleeding, mucus, faecal urgency, abdo pain, nocturnal defecation
- Extraintestinal manifestations (arthritis, uveitis, erythema nodosum, pyoderma gangrenosum)
- Primary sclerosing cholangitis (3-7% patients with UC)
What is the onset of UC?
•Often insidious onset (not clear cut)
What are the investigations for UC?
ØStool cultures + CDT
ØFaecal calprotectin
ØCRP
ØFBC
ØAlbumin
ØFlexible sigmoidoscopy/colonoscopy
Who is most likely to get UC?
- Any age (peak teens/early adulthood)
- M:F 1:1
- Positive effect of smoking! (ex-smokers 70% increased risk of UC)
- Appendicectomy protective (before age 20)
- 10-15 fold risk in 1st degree relatives (2% lifetime risk)
Does UC or CD have a relapsing/remitting course?
Both
Whats the diagnosis?
Ulcerative Colitis
What is the treatment for severe UC?
- Admit
- Hydrocortisone 100mg iv qds
- Heparin s.c.
- Stool chart
- AXR
Daily CRP
What should be avoided in severe UC?
•AVOID: NSAID’s, opiates, anti-motility agents
What percentage of severe UC admissions -
- Response to steroids
- Colectomy
- Mortality
- Response to steroids 67%
- Colectomy 29%
- Mortality 1%
