Diarrhoea, Constipation, Coeliac Disease and IBS Flashcards
What is diarrhoea?
A change in bowel habit resulting in substantially more frequent and looser stools than usual
More about the consistency of the stools than the frequency
How does WHO define diarrhoea?
The passage of 3 or more loose or liquid stools per day (or more frequent passage than is normal for the individual)
How can diarrhoea be classified?
Acute <14 days
Persistent >14 days but <28 days
Chronic >28 days
What is the pathophysiology of diarrhoea?
More than one mechanism than can cause diarrhoea Increase osmotic load in gut lumen Increase in secretions Inflammation of intestinal lining Increased intestinal motility
What is acute diarrhoea?
Diarrhoea that is self-limiting and usually resolves within 72 hours
What causes acute diarrhoea?
Usually due to infection or ingestion of toxins (contaminated food)
Infection can be bacterial (e.g. E. coli, Salmonella) or viral (e.g. rotavirus, norovirus)
Other causes include drugs, parasites and anxiety
How is acute diarrhoea treated?
Symptomatic relief
What diseases associated with acute diarrhoea are ‘notifiable’?
Dysentery
Food poisoning
What is travellers diarrhoea?
Diarrhoea experienced by travellers
Early onset, usually within the first few days of a trip and usually resolves within 7 days
What are the symptoms of travellers diarrhoea?
As per acute diarrhoea but can also contain blood (dysentery)
What is travellers diarrhoea dependent on?
Destination, age and diet
What causes travellers diarrhoea?
Enterotoxigenic E.coli and campylobacter
Salmonella
Enterohaemorrhagic E. coli and shigella
Viruses, Protozoa and helminths (worm-like parasites)
What can occur as a result of certain infections?
E.g. giardiasis and amoebic dysentery
Can cause persistent or recurrent diarrhoea or systemic complications
Is antibiotic prophylaxis used in travellers diarrhoea?
Rarely recommended
How can travellers diarrhoea be avoided?
Wash hands thoroughly using soap
Antiseptic wipes/gel if there are no washing facilities available
Avoid drinking local water, even for cleaning teeth
Avoid ice cubes, diary produces, ice cream, home distilled drinks and salads
Eat fresh foods
Avoid shell fish and shellfish unless you are sure they are fresh and have not been near a sewage outlet
Only use clean, hygienically run establishments
What is chronic diarrhoea?
Recurrent or persistent diarrhoea
What are some of the causes of chronic diarrhoea?
IBS
IBD
Malabsorption syndromes e.g. coeliac disease, lactose intolerance
Metabolic disease e.g. diabetes, hyperthyroidism
Laxative abuse
How should you question a patient about their diarrhoea symptoms?
Ask about, Stool frequency Nature e.g. presence of blood, mucus Occurrence e.g. isolated or recurrent? Duration Onset Timing Food Recent travel Medication
When is referral required in adults?
If there symptoms have lasted >72 hours in healthy adults, >48 hours in elderly and >24 hours in diabetes
If there diarrhoea is associated with vomiting and fever
If they have a history of changes to their bowel habits (especially if over 40/50)
If they have blood/mucus in their stools
If you suspect an ADR
If they are elderly and have alternating diarrhoea and constipation (could be faecal impaction)
If they have unintentionally lost weight
If they have recently been in hospital or had antibiotic treatment (could be a HCAI such as C. difficile)
If there is evidence of dehydration
If they are in severe pain or have rectal pain
What is the primary aim in diarrhoea treatment?
Prevent dehydration
How can diarrhoea be treated?
Oral rehydration therapy Loperamide Morphine Diphenoxylate Absorbents Antibiotics
What should Oral Rehydration Solutions (ORS’s) do?
Enhance the absorption of water and electrolytes
Replace electrolyte deficit adequately and safety
Contain alkalinising agent to counter acidosis
Be slightly hypo-osmolar (about 250mmol/L) to prevent the possible induction of osmotic diarrhoea
Be simple to use in the hospital and at home
Be palatable and acceptable, especially to children
Be readily available
Should be sipped over a period of time rather than drank all at once
What do Oral Rehydration Solutions (ORS’s) generally contain?
Sodium and potassium to replace essential ions
Citrate/bicarbonate to correct acidosis
Glucose or another carbohydrate e.g. rice starch
Which patients can Oral Rehydration Solutions (ORS’s) be used for?
Patients of any age
What is the usual dose of an Oral Rehydration Solution (ORS) after a very loose motion?
200-400ml
Which patient group must be take extra care in when using Oral Rehydration Solutions (ORS’s)?
Diabetics
Blood glucose levels should be monitored carefully (some sachets contain glucose)
What is loperamide?
An anti-motility agent
It is a synthetic µ opioid receptor agonist
Has a direct action on opiate receptors in the gut wall
What can be said about the pharmacokinetics of loperamide?
Extensive first pass metabolism so little reaches systemic circulation
What are some contraindications to the use of loperamide?
Active UC
Antibiotic associated colitis
Conditions where inhibition of peristalsis should be avoided
Conditions where abdominal distension develops
These are all underlying conditions where you do not want to affect gut motility
What are some cautions to the use of loperamide?
Avoid in,
Bloody/suspected inflammatory diarrhoea
Significant abdominal pain
What are some of the side effects of loperamide?
Abdominal cramps
Dizziness
What MHRA warning was issued surrounding loperamide?
Serious cardiac adverse reactions associated with high doses in abuse/misuse
When are antibiotics used in diarrhoea?
Used when the diarrhoea is caused by an infection
In severe infection (fever >39° and prolonged symptoms, in the elderly or immunocompromised)
What should be done before antibiotics are given in diarrhoea?
A stool sample should be taken and causative organism identified
Why is empiric use of antibiotics in diarrhoea not recommended?
Risk of antimicrobial resistance
Prolong symptoms as may cause GI side effects
Pre-dispose to C. difficile infection
How does morphine act against diarrhoea?
Has a direct action on intestinal smooth muscle
What is the morphine content per recommended dose of products available OTC for diarrhoea?
Around 0.5-1mg
What is a side effect of opiates?
Constipation, explains their use in the treatment of diarrhoea
What is diphenoxylate?
A synthetic derivative of pethidine (opioid)
How is diphenoxylate available to treat diarrhoea?
As a combination product, Co-phenotrope, with atropine