Diarrhoea Flashcards
What is diarrhoea?
‘Abnormal passage of loose or liquid stools more than three times daily and/ or a volume of stool greater than 200g/day’
What is normal for patient- change from baseline
Acute diarrhoea
Less than 4 weeks
Most acute diarrhoea infectious
Self limiting, ?investigate after 1 week
Chronic diarrhoea
More than 4 weeks
Chronic pathology
Always investigate
Viral causes of diarrhoea
Rotavirus
Norovirus
Enteric adenovirus
Parasitic causes of diarrhoea
Cryptosporidium parvum
Chronic
- giardia lamblia
- entamoeba histolyticia
Bacterial causes of diarrhoea
Salmonella
Shigella
Campylobacter
Staph aureus
Causes of osmotic diarrhoea
Lactose intolerance
Some laxatives
Bile salt diarrhoea
Bile salt test
SeHCAT scan
Stools in malabsorption
Large, greasy, pale stools
Steatorrhoea
Causes of fatigue
Malabsprtion
Deficiency- iron, B12
Lack of sleep
Causes of chronic diarrhoea: colonic
Inflammatory bowel disease
Microscopic colitis
Colorectal cancer
Causes of chronic diarrhoea: small bowel
Coeliac
Crohn’s
Bile salt malabsorption
Lactose intolerance
Small bowel bacterial overgrowth
Causes of chronic diarrhoea: pancreatic
Chronic pancreatitis
Pancreatic cancer
Cystic fibrosis
Causes of chronic diarrhoea: endocrine
Hyperthyroidism
Diabetes
ADdison’s disease
Hormone secreting tumours
Causes of chronic diarrhoea: other
Drugs
Alcohol
Facticious
Mechanisms of diarrheoa
Osmotic- lactose intolerance
Malabsorption- steatorrhoea
Secretory- E.coli
Inflammatory
Neoplastic
Ischaemic
Post irradiation
Not IBS
Does not cause diarrhoea at night
Does not cause weight loss
Stool tests
Microscopy and culture
Faecal elastase
Faecal calprotectin
Imaging
Colonoscopy
Barium enema
Small bowel enema
CT
Video capsule
MRI small bowel
SeHCAT scan
Ulcerative colitis
Affect only colon
Continuous inflammation
Any age, peak 20-40
Mucosal inflamamtion
Bloody diarrhoea
`Extraintestinal manifestations
Crohn’s disease
Any part of GI tract
Any age, peak 20-40
Transmural inflammation, deep ulcers
Skip lesions
Treatment for IBD
5 ASA preparations - UC
Corticosteroids
Azathioprine/ 6-mercaptopurine
Methotrexate
Biologics
Surgery