Diarrhoea Flashcards
Define diarrhoea.
An increase in the amount of stool passed daily to over 300 g of stool/day. This is usually accompanied by increased frequency and loosening of the stools.
Normal: 3/day to 3/week
What other types of stool may diarrhoea be mistaken for?
Haematochezia
Melaena
Steatorrhoea
Loose stools (soft faeces with no increase in frequency or quantity)
List 6 main mechanisms of diarrhoea.
Infection Inflammation Increased bowel motility Malabsorption Medications
For each of the mechanisms, list some causes: Infection Inflammation Increased bowel motility Malabsorption Medications
- Infection Infectious diarrhoea - Inflammation Inflammatory bowel disease Diverticular disease - Increased bowel motility IBS Hyperthyroidism - Malabsorption Coeliac disease Pancreatic insufficiency Overflow Diarrhoea Hard faeces stuck in the bowel Colon cancer or ovarian cancer - Medications Laxatives Colchicine Digoxin Antibiotics Metformin Thiazide diuretics
What is the differential diagnosis for diarrhoea in young people?
Infective diarrhoea Irritable bowel syndrome Inflammatory bowel disease Coeliac disease Medications Hyperthyroidism
Describe the distribution in the incidence of inflammatory bowel disease.
Bimodal distribution with peaks in the 20s and 40s
What is the differential diagnosis for diarrhoea in elderly people?
Neoplastic disease (villous polyps, colorectal cancer, pancreatic cancer) Diverticular disease Ischaemic colitis Overflow diarrhoea Bacterial overgrowth Microscopic colitis
What are the first factors to consider in the immediate management of a patient with diarrhoea?
ABC
Dehydration – check heart rate, blood pressure, mucous membranes
Electrolytes and pH disturbance
What are the three major consequences of severe diarrhoea?
Shock
Acidosis
Hypokalaemia
List some questions that you would ask about the character of the stools.
Have the stools been mucoid or jelly-like?
Have the stools been foul-smelling, floating and difficult to flush away?
Have the stools been unusually pale?
Has there been blood in the stool?
State two causes of mucoid diarrhoea.
Salmonella
Villous polyps
What could cause foul-smelling and floating diarrhoea?
Malabsorption (due to coeliac disease, biliary outflow obstruction, pancreatic insufficiency)
What do pale stools suggest?
Biliary outflow obstruction
NOTE: you could ask about dark urine as well
List some questions that you would ask about the patient’s bowel habit.
Have you been having diarrhoea at night?
Have you found yourself rushing to the toilet to poo?
After passing motions, do you ever feel like you haven’t fully evacuated your bowels?
Have the bowel habits been variable? Have you also experienced periods of constipation?
How often do you get diarrhoea?
Which causes of diarrhoea is faecal urgency suggestive of?
Infective diarrhoea
IBD
What is tenesmus* and what does it suggest?
*tenesmus = recurrent inclination to empty bowels
Continual or recurrent feeling of having to empty your bowels even if there is nothing coming out
This suggests that there is a space-occupying lesion in the rectum
Which diagnoses are associated with causing with a variable bowel habit with bouts of both diarrhoea and constipation?
IBS (more in the young) Colorectal caner (more in the elderly)
List some key associated symptoms that you should ask the patient about.
Vomiting
Abdominal pain
Unintentional weight loss
Eye, skin and joint problems
Which differential causes diarrhoea and vomiting?
Gastroenteritis (infective diarrhoea)
What would RIF pain associated with diarrhoea suggest?
Crohn’s disease (the pain is caused by inflammation of the terminal ileum)
What would LIF pain associated with diarrhoea suggest?
Diverticular disease
Why is it important to classify how rapidly a patient suffering from diarrhoea has lost weight?
Acute diarrhoea (due to infection) can cause rapid weight loss Weight loss over months is suggestive of chronic disease (e.g. IBD, cancer)
List some extra-GI features of inflammatory bowel disease.
Uveitis/Scleritis/Episcleritis Erythema nodosum Pyoderma gangrenosum Aphthous ulcers Enteric arthritis
List some risk factors for diarrhoea.
Recent travel abroad Eating unusual food Knowing people with similar symptoms Stress Low-fibre diet Medications
