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
How do adsorbents act in diarrhoea?
Adsorb microbial toxins and microorganisms
Give 2 examples of adsorbents used in diarrhoea.
Kaolin (kaolin and morphine)
Bismuth subsalicylate
What advice can we give as pharmacists for the general management of diarrhoea?
Drink plenty of clear fluids
Avoid drinks high in sugar
Avoid milk and milky drinks
Eat light, easily digested food
In gastroenteritis infections, precautions including not returning to work until symptom free for 48 hours, hygeine advice and cleaning of sanitary equipment
Make patients aware of the danger symptoms and who to go to if they experience these
Why is it important to check a patients medication history who is experiencing diarrhoea?
Diarrhoea can reduce the absorption of some medicines
What is Clostridium difficile?
A spore forming anaerobic gram-positive bacterium
Asymptomatic commensal in 2-3% of the adult population
What can Clostridium difficile cause?
Leading cause of antibiotic associated diarrhoea
Common cause of HCAI’s
Can lead to pseudomembranous colitis (swelling or inflammation of the large intestine due to an overgrowth of C. diff)
What are some of the risk factors for Clostridium difficile infection development?
Antimicrobial choice Antimicrobial duration (don't want unnecessary continuation) Acid suppressing medications e.g. PPI's Age Length of stay Recent hospitalisation
How can Clostridium difficile infection be managed?
Depends on the severity of the infection
Concomitant antimicrobials and acid suppressing medication should be stopped where possible
Anti-motility medications should be stopped
Maintain adequate fluid balance
Targeted C. difficile antimicrobial treatment
Appropriate infection control procedures including hand washing (with soap and water) and isolation
What antimicrobial agents are used to treat Clostridium difficile infection?
Oral metronidazole (1st line for mild-moderate CDI) Oral vancomycin (mild-moderate or severe CDI) IV metronidazole and oral vancomycin (critically unwell patients) Oral fidaxomicin (not used very often, recurrent CDI and severe CDI with a high risk of reoccurrence)
How does fidaxomicin act against Clostridium difficile?
Macrolytic antibiotic that inhibits C. difficile sporulation
Other than the traditional antimicrobial agents, how else can Clostridium difficile infection be treated?
Probiotics (restore gut microbiome, role uncertain)
FMT (still at the clinical trial stage)
IV immunoglobulin (used in severe or recurrent cases of colitis where other treatments have failed)
What is constipation?
The passage of hard stools less frequently than normal for that patient, typically less than 3 bowel movements per week
In which patient groups is constipation more common?
Women, especially when pregnant
Older people
What are some of the symptoms of constipation?
Abdominal discomfort and distension Abdominal cramping Bloating Nausea Difficulty passing stool
What is the Bristol Stool Chart and what do the different levels indicate?
Classifies stools according to shape and size to determine whether the patient is constipated, has diarrhoea or is producing healthy stools
Type 1 and 2 indicate constipation
Type 3 and especially 4 are the preferred types of stools as they are easiest to pass
Type 5 and 6 are symptomatic of diarrhoea
Type 7 may be a sign of cholera or food poisoning
What is functional (idiopathic) constipation?
Constipation with no anatomical or physiological cause known
What is secondary constipation?
Constipation induced by a particular condition or medicine
What are some non-medical factors which pre-dispose constipation?
Inadequate fluid intake
Inadequate dietary fibre
Dieting
Changes in lifestyle and activity levels
Suppressing the urge to defecate (common in children)
What are some medical conditions which pre-dispose constipation?
Coeliac disease Depression Diabetes IBS Parkinson's disease Hypercalcaemia Hyperkalaemia Hypothyroidism (These patient groups may need a laxative long term)
What are some medications which pre-dispose constipation?
Antacids containing aluminium and calcium
Antihypertensives (diuretics, CCB’s)
Antidepressants (tricyclics, MAOI’s)
Antimuscarinics (procyclidine, oxybutynin)
Antiparkinsonian medicines (levodopa, dopamine agonists, amantadine)
Opioid analgesics (laxative commonly co-prescribed)
Iron
How can we assess constipation in patients?
As patient about bowel habits
Perform an examination
Try to identify cause
Check for red flags including unexplained weight loss, rectal bleeding, family history of colon cancer or IBD and signs of obstruction
What are the treatment aims in constipation?
Restore normal defecation frequency
Achieve regular, comfortable defecation
Avoid laxative dependence
Relieve discomfort
What non-pharmacological treatments can be used in constipation?
Increase dietary fibre
Ensure adequate fluid intake
Lifestyle measures including exercise
What pharmacological treatments can be used in constipation?
Laxatives
What are the 4 types of laxatives?
Bulk-forming
Stimulant
Osmotic
Faecal softening
What are bulk-forming laxatives?
Increase faecal mass through water binding to stimulate peristalsis to stimulate motility
How long do bulk-forming laxatives take to work?
Several days for the full effect
What must be maintained when taking bulk-forming laxatives and why?
Fluid intake
Can worsen constipation if fluid levels are not kept high
Can bulk-forming laxatives be used long term?
Yes
Give 2 examples of bulk-forming laxatives.
Ispaghula husk (Fybogel) Methylcellulose (also acts as a softener)
What are stimulant laxatives?
Increase intestinal motility via muscle contractions
How long do stimulant laxatives take to work?
A few hours
Patients usually take them before bed and they work by morning
What is a side effect of stimulant laxatives?
Abdominal cramps
Can stimulant laxatives be used long term?
Prolonged use should be avoided as it can lead to diarrhoea, fluid and electrolyte imbalance
Give 3 examples of stimulant laxatives.
Senna (commonly co-prescribed with opioid analgesics)
Dantron (terminally ill patients only)
Bisacodyl
What are osmotic laxatives?
Works with colonic lumen to retain and draw water into the intestine by osmosis
What must be maintained when taking osmotic laxatives?
Good fluid intake
Give 4 examples of osmotic laxatives and their time to effect.
Macrogel powders - 1-3 days
Lactulose (disaccharide, caution in diabetics) - 2-3 days
Phosphate enema or suppository - 15-30 minutes
Magnesium hydroxide - 3-6 hours
What are faecal softening laxatives?
Stimulate peristalsis by increasing faecal mass, act to lower surface tension and allow water and fat to penetrate faeces
Give 3 examples of faecal softening laxatives and their time to effect.
Docusate sodium (faecal softener and stimulate) - 1-3 days
Glycerol suppository - 1 hour
Arachis oil enema - 30 minutes
When is an arachis oil enema contraindicated?
In patients with a nut allergy
What are some of the complications of constipation?
Faecal impaction
Haemorrhoids
Rectal prolapse
Anal fissures
What is coeliac disease?
An autoimmune condition affecting the small intestine
The body’s immune system attacks itself when gluten is eaten (adverse reaction to gluten)
What is the cause of coeliac disease?
An interaction between genetic predisposition and environmental triggers
Is coeliac disease an allergic condition?
The reaction is not an allergic reaction and does not cause anaphylactic shock
Who does coeliac disease affect?
Around 1% of all Northern Europeans and North Americans
How is coeliac disease diagnosed in adults?
Serology (looking for the presence of certain antibodies)
Endoscopy for small intestine biopsy (2nd part of duodenum, at leats 4 biopsies should be taken to ensure the patient is not misdiagnosed)
Repeat biopsy on a gluten free diet
Gluten challenge (>10g/day, 6/52, to allow for testing and a conclusive diagnosis)
What are some of the symptoms of coeliac disease?
Headaches
Diarrhoea
Abdominal pain
Lethargy
How do symptoms differ between patients?
Not every patient has symptoms
Vary from person to person and from mild to severe
They may last a few hours or a few days
What are some of the complications of coeliac disease?
Long term malabsorption and osteoporosis
Refractory coeliac disease
Ulcerative jejunitis
Enteropathy associated T-cell lymphoma
Autoimmune disease (T1DM, thyroid disease)
The longer you eat gluten, the higher the risk of triggering another autoimmune disease
Is there a cure for coeliac disease?
There is no cure
What happens if gluten is reintroduced into the diet at a later date?
The immune system will react and the gut lining will become damaged again
How is coeliac disease treated?
Treatment is a lifelong gluten free diet and there is research underway to develop a vaccine
Which foods are gluten free?
All fresh meat Fish Cheese Eggs Milk Fruit Vegetables Specially manufactured wheat starch
How can patients identify gluten free products?
Crossed grain symbol
Why are patients reluctant to gluten free diets?
Poor taste meaning lots of sugar has to be added to improve it
Expensive
Difficult to eat out
No agreed international consensus on permissible levels
Range of symptoms with ingestion
Low fibre, low vitamin D and high calories
Can you get gluten free foods on prescription?
Yes but as of Dec 2018 this is restricted to bread and mixes only
What is irritable bowel syndrome (IBS)?
A chronic condition characterised by at least 6 months of abdominal pain and bowel symptoms (diarrhoea, constipation or a combination of both)
What causes IBS?
The cause is unclear and can differ patient to patient
IBS is a very poorly understood condition
How can IBS be treated?
As we don’t know the underlying cause, treatment is aimed at symptomatic relief
No ‘gold’ standard as symptoms vary
Includes,
Dietary changes and exercise
Antispasmodics (e.g. mebeverine, hyoscine, peppermint oil)
Anti-diarrhoeal (e.g. Loperamide)
Laxatives (e.g. bulk-forming, stimulant, osmotic)
Probiotics
What are antispasmodics?
Smooth muscle relaxants
