GI Diseases Clinical Flashcards
Explain why upper GI conditions occur?
Due to acid:
-wrong location eg through oesophagus reflux/ overflow into duodenum
-overproduction
-faults with protective mechanisms- Lower Oesophageal Sphincter (LOS) and pyloric sphincter- if not working acid can pass through, protective lining (gastric cytoprotection is faulty)
What is dyspepsia?
A broad term for a range of symptoms in upper GI tract:
upper abdominal pain, gastric reflux, heart burn, nausea and vomiting, wind
What is the epidemiology of upper GI conditions?
Prevalence varies from 20-40%
Quarter of which will have peptic ulcer disease
90% of patients self medicate, this can make potentially serious problems
What is the epidemiology of gastric cancer?
UK incidence-10/10000
4400 deaths from stomach cancer
17th most common cancer cause death
54% are preventable
Describe the aetiology of gastric cancer:
More common in smokers and drinkers (decrease in protective mechanisms)
Salt intake
Related to H Pylori infection
Less common in vegetarians
More common in 45 years + and x2 prevalence in men
Name common upper GI conditions:
Gastro-oesophageal reflux disease (GORD) 10-20%
Duodenal stomach ulcer disease (PUD) 10-25%
Gastritis 30%
Functional dyspepsia 30%
Oesophageal and gastric cancer 2%
What is the function of HCl and parietal cells?
Parietal cells secrete HCl and intrinsic factor- secreted from fundus
They activate pepsinogen and kills bacteria
Intrinsic factor aids absorption of vitamin B12
Name the 4 phases of controlling acid secretion via parietal cells:
Cephalic phase
Gastric phase
Intestinal phase
Basal state
What occurs in the cephalic phase?
Nervous control, parasympathetic
Thought, smell, taste or sight of food
What occurs in the gastric phase?
Local control, parasympathetic
Distention of stomach and chemical makeup
What occurs in the intestinal phase?
Hormonal control
Food in the duodenum (chyme) causes secretion of somatostatin which inhibits acid production (-ve feedback, enterogastric reflex)
What occurs in the basal state?
Occurs in time between meals, level of acid secretion during these times are regulated by body weight, nº parietal cells and time of day
What is gastrin and how is it produced?
Produced in response to vagal stimuli, a rise in pH (decrease in acidic conditions) and ingested protein and calcium
Stimulates growth of gastric mucosa- protective function
Describe how Ach has an affect on H2:
Vagal stimulation causes Ach to have a direct effect on parietal cell (minor)
Major effect is Ach release onto enterochromaffin like cells
Gastrin has same effect
Describe how somatostatin has an affect on acid production:
PGE2 receptor on parietal cells, somatostatin binds here as its a PG, it stops acid production, negative feedback due to contents of duodenum
Describe what gastric cytoprotection is:
Auto digestion of the stomach is prevented by a thin layer (500microns) above the mucosa surface (neutral)
Complex matrix of bicarbonate and mucus- unstirred layer
How can a stress ulcer be formed in shocked/ critically ill patients?
H+ is normally taken away by submucosal blood flow
In shocked pts, there is a decrease in blood flow, so necrosis in mucosa by increase in H+ conc and decrease in O2
How does somatostatin offer gastric cytoprotection?
Increase mucus secretion
Increase bicarbonate
Increase blood flow
Decrease in acid
How does the Lower Oesophageal Spincter (LOS) have a role in oesophageal protection?
Permanent state of contraction, relaxes to allow food
Reflux can be caused this way
What is gastritis?
Inflammation of the gastric mucosa
What is the pathophysiology of gastritis?
It is a precursor for ulceration
80% of cases due to H pylori-> chronic gastritis-> PUD-> gastric cancer
What are the symptoms of gastritis?
For many they can be asymptomatic
Symptoms include indigestion, sickness, burning
What other health issues can gastritis cause?
40x increased risk of PUD
6x increased risk of gastric cancer
How does Helicopactor Pylori survive in the stomach?
Adapted to survive in acidic conditions
They protect themselves by hydrolysing urea to produce ammonia, which causes a buffer H+ions
Have flagella to burrow into mucosa in the antrum
How does H.Pylori cause a duodenal ulcer?
Chronic inflammation, decrease somatostatin, increase in gastrin production, increase stomach acid production, chronic inflammation in duodenum, where H.Pylori moves into the duodenum and reduces local protection-> duodenal ulcer
What are the 2 different types of H Pylori infection and why?
Depending on the natural acidity status of the body
HP prefers decreased acidity, it won’t affect a healthy duodenum but will affect it if the stomach has passed through and damaged it
For many it leaves the acid unchanged so asymptomatic so no ulcers
How does HP cause gastritis?
Damaged cells and decrease acid production, decrease in mucosa, which long term leads to gastric ulcer and gastric cancer
Who does HP normally infect?
50% of population over 60 infected, almost all over 80
Can get it through childhood/kissing/contaminated vomit
Some strains are more pathogenic than others
How can the HP bacteria be tested for and identified?
Breath test or stool antigen test
Give radio labelled urea and CO2 (radiolabelled) will be produced in breath
Stool needs to be stored at -20ºC before testing (most common)
For both tests pts need to avoid antibiotics for 4 weeks before to avoid a false negative
How would you improve an ulcer if someone has the HP infection?
Eradication, it is the cure
How many people who have duodenal and stomach ulcers also have the HP infection?
Duodenal, more than 90%
Stomach ulcer, 70-80%
What is the epidemiology of PUD?
10-15% of population will suffer from it
GU rare in under 40
DU predominately in males between 20-50
What are the factors causing PUD?
Gastric hyper secretion (DU)
Reduced mucosal resistance (GU) e.g smoker
What is the prognosis of PUD?
Bleeding (perforation, lining splits open) in 10-15% of pts
5-10% with DU will perforate, 1 in 7 will die
5-15% of GU eventually found malignant
60% of pts with DU will relapse after a 1 year
50% of pts with GU will relapse after 2 years
What are the risk factors in PUD?
HP is the major cause
NSAIDs are common cause
More common in smoker- increase number increases prevalence
Salt- can change acid secretion as suppressive effect on parietal cells
Genetic link- people with parents with PUD are 3x more likely
No evidence for stress vs PUD
Which drugs can induce dyspepsia?
Cause peptic ulcers:
NSAIDs
Sulfasalaizine
Iron preparations
Corticosteroids
K (particularly in mr forms)
Bisphosphonates
May reduce LOS pressure:
Theophylline
Ca agonists
Nitrates
How many patients with RA suffer from PUD and what is the safest NSAID to use?
1/3
Ibuprofen is the safest
What are the gastric symptoms of PUD?
Pain on eating
Epigastric area (below sternum but above naval)
What are the duodenal symptoms of PUD?
Pain occurring between meals and at night
Localised dull pain
What are other symptoms for both gastric and duodenal PUD?
Bloatedness
Nausea
Anorexia
Belching
Haematemesis (blood in vomit)
Melaena (dark sticky faeces)
What is GORD?
5-10% of adults have symptomatic reflux
Caused by gastric juice and occasionally duodenal contents in the oesophagus
Defective LOS may be the most important abnormality
Name factors which can contribute to lowering the pressure of the LOS:
Dietary factors (fat, chocolate, caffeine, alcohol, large meals)
Cigarette smoking
Endocrine factors (high levels of oestrogen and progesterone e.g pregnancy, HRT, Oral contraception)
Drugs
What is Hiatus Hernia?
Part of stomach is pushed up through diaphragm
Prevents LOS from closing
Allowing stomach contents to escape
Affects 30-50% of population
Majority of pts are asymptomatic
May present as GORD
Which drugs can contribute to GORD?
Anticholinergics
B2 agonists
Diazepam
CCBs
Nitrates
Alcohol
Progesterones
COC
Theophylline
Which drugs can cause oesophageal ulceration?
NSAIDs
Bisphosphonates
Clindamycin
Clotrimazole
Doxycyline
Potassium
Tertacycline
Theophylline
Antibiotics responsible for 50% of drug induced oesophagitis, especially clindamycin capsule
What are the symptoms in GORD?
Motility of oesophagus may be abnormal
Gastric emptying is delayed in 40% of pts
Main symptom is heart burn
May also suffer dysphagia or odynophagia (pain on swallowing)
What are complications of GORD?
Barrett’s oesophagus (RF for cancer cell lining of oesophagus changes)
Haemorrhage
Stricutre
What is the diagnosis for GORD?
Endoscopy is the only diagnosis
What is functional dyspepsia?
Not associated with risk of cancer
Half of patients with chronic dyspepsia with no evidence of organic disease with investigations done
Could be hypersensitivity to gastric acid
What are the 4 groups of symptoms for functional dyspepsia?
These all can overlap
Ulcer like
Dysmotility like
Reflux like- ongoing heart burn/ reflux but no GORD with investigation
Non-specific
What is the treatment for functional dyspepsia?
Eradicate HP if present
Neutralise acid or prevent production (symptomatic relief)
Periodic monitoring (safety netting)
What should be the management of stomach and duodenum ulcers?
Identify and eradicate HP
Stop inappropriate therapy
Reduce production of acid to reduce gastritis and enable mucosa to repair- block H2 or PPI
Once ulcer is healed (8weeks) then test for HP
Describe the eradication therapy for HP?
2 antibiotics and a PPI
Normally amoxicillin and clarithromycin
85% effective
What should be the management of stomach and duodenum ulcers if there are no causes?
PPI can be prescribed for 4-8 weeks
If still unhealed look for adherence, stopping NSAIDS e.g OTC, or other diseases present e.g Crohns
What should be prescribed if the symptoms of ulcers heals but then the symptoms come back again
Low dose PPI
Give diet advice for the management of GORD:
Eat small meals
Avoid foods which lower LOS pressure (alcohol, caffeine etc)
Avoid fatty foods which slow gastric motility
Avoid eating within 4 hrs and drinking 2 hrs before going to bed
Reduce alcohol intake
Give other lifestyle advice for the management of GORD:
Avoid drugs which lower LOS pressure
Avoid tight fitting clothes
Attention to posture (bend form knees)
For nocturnal heart burn, raise top head of bed by 15-23cm
Stop smoking
What are antacids made up of and how do they work?
Al, Mg, Na and Ca salts
Neutralise acid, releasing CO2 (eructation aka burp)
Increase in LOS pressure by gastric alkalinisation
Mucosal protection, stimulate PG synthesis
Which formulation of antacids work quicker but what negative aspect does it come with?
Liquids work quicker but have a shorter DoA
Why should antacids only be taken for short term use?
As they only releive symptoms in the short term, can cause an acid rebound
When are antacids best taken?
An hour after a meal, when gastric emptying is slow, so they remain in the stomach for longer, DoA = 3hrs
What are common side effects with antacids and how are these resolved?
Constipation with Al based salts
Diarrhoea with Mg based salts
Can be used in combo to counteract each other
What medical conditions can antacids interact with and why?
Al binds to phosphate in gut- osteoporosis
Al can be absorbed- neurotoxicity
Rebound GA secretion with prolonged use
Na- avoid in patients with cardiac problems and hypertension
Are antacids safe to take during pregnancy?
Generally safe but got to look at sodium content
How do alginates work?
Formulated with antacids
Form a high pH viscid mass (raft), trapping air bubbles and CO2 from the reaction of antacid with the stomach contents
So can float to the top of stomach and protects oesophageal mucosa from stomach contents
How does dimeticone work?
Anti foaming agent
Reduces surface tension
Allows bubbles to escape- reduces feeling of bloating
Name examples of H2 receptor antagonists:
Cimetidine, Ranitidine, Famotidine, Nizatidine
How do H2 receptor antagonists work?
Compete for H2 receptor on parietal cells, overidden by powerful stimulus e.g large meal (competition)
Has a longer duration than antacids
What are the healing rates of H2 antagonists used in PUD?
High healing rates, no reduction in relapse
What are the healing rates of H2 antagonists used in GORD?
After 12 weeks, 80-90% of pts with mild oesophagitis improved
Not effective in moderate to severe GORD
Only use if an inadequate response to PPI (NICE)
What are the side effects of different H2 antagonists?
Generally safe 1-7% of pts experience ADRs
Headache/ dizziness
Cimetidine- Gynaecomastia, breast tissue in men (0.2%), impaired libido
Nizatidine- sweating/ abnormal dreams
Confusional states in elderly
Name interactions of Cimetidine?
Binds to P450
Phenytoin, theophylline, warfarin
Enhances their effects
Name a H2 antagonist sold OTC and its dosage:
Ranitidine- Zantac 75
Symptomatic relief of HB, dyspepsia, hyperacidity
6 days continuous treatment, maximum 2 days daily
Name some examples of PPI and their structure:
Omeprazole, Lansoprazole, Esomeprazole, Pantoprazole
Enteric coated preparations, due to being destroyed by stomach acid (acid labile)
Absorbed in SI
Take 1-2 days to reach full effect
Describe the MoA of PPIs:
Blocks H-K ATPase enzyme
Prolongued suppression acid secretion
-20mg omeprazole causes 80% decrease acid secretion for a day
-40mg 100% decrease
Heals ulcers more rapidly than H2, but healing rate is same at 8 weeks
PPIs superior in treatment of reflux/GORD
Lisenced to treat acid aspiration if going under general anaesthetics
What are short term side effects of PPIs?
Nausea, diarrhoea, flatulence, epigastric pain, dry mouth, headache
Arthralgia and myalgia
What can be the concerns of taking PPIs long term?
Bacterial overgrowth as may increase risk of salmonella/ HP
When is the best time of day to take a PPI?
Before food as food can decrease bioavailability
What PPIs are available OTC and at what dose and indication?
Omeprazole 10+20mg +esomeprazole
Reflux symptoms in over 18s
Swallowed whole with plenty of liquid
20mg daily until symptoms have improved then 10mg
When should you refer to the GP for pts wanting to take PPIs OTC?
If after taking them for 2 weeks still no relief
If treatment required continuously for 4 weeks then refer
Pt is over 45 and present with new or changes symptoms (or child)
Continuous dyspepsia (5 days)
Weight loss, appetite, signs of anaemia
Pain on exercise, cardiac origin, pain radiating to arms (heart attack?)
Blood in vomit/ stools
Name other drugs which can be prescribed for upper GI conditions:
Metoclopramide+ domperidone
Sucralfate
Bismuth
Misoprostol
Describe metoclopramide+ domperidone as a treatment for GI conditions:
Increase gastric emptying and LOS tone
Describe sucralfate as a treatment for GI conditions:
Not very common
Polymerizes below pH 4 to form a sticky gel
Adheres to ulcer- physical protection
Describe bismuth as a treatment for GI conditions:
Not very common
May act similar to sucralfate
Strong affinity for mucosa- especially ulcers
May blacken teeth and stools
Describe misoprostol as a treatment for GI conditions:
Promotes ulcer healing by stimulating protective mechanisms- sometimes used with NSAIDs
What is the main treatment used for FD, gastritis and PUD?
H2 antagonists or PPI
What is the main treatment used for GORD?
PPIs or alginates (not H2)
What is the function of bacteria in the LI?
Ferment non digestible polysaccharides, some metabolites absorbed
Produce vitK and biotin (vitB7), which can be absorbed
Produce gases from undigested polysaccharides
Essential for development of caecum and lymphatics
What is constipation?
A symptom, not a disease
Difficulty opening the bowels:
-less than 3 times a week
-straining to open bowels for more than 25% of occasions
-hard or pellet like stool for more than 25% off occasions
What is chronic constipation?
More than 4 weeks
Generally more than 12 weeks in the last 6 months
What is the epidemiology of constipation?
1 in 7 adults
1 in 5 older people
1 in 3 children
More common in women than men
What is imaginary constipation?
Elderly patient may not go as frequently when younger due to not eating as much but this is expected
Describe the types of food that increase chances of having constipation:
Low fibre
High animal fat
Inadequate fluid intake
Caffeine/ alcohol (both diuretics)
Name some medications which can cause constipation:
Antacids (Ca and Al)
Antispasmodics
Antidepressents
Anticolinergics^
Iron tablets e.g ferrous sulfate
Diuretics (encouraging patient to urinate so decreased fluid)
Painkillers (codeine)
CCBs
ACEi
Ulcer healing (PPI)
Antipsychotics
Describe the aetiology of constipation:
Intestinal obstruction:
-scarring from IBD, diverticulitis or post surgery
-adhesions
-intestinal cancers
-abdominal hernia
-gall stones wedged in intestine
-volvous
-foreign bodies
-haemarroids
What are diseases that can cause constipation?
Diabetic autonomic neuropathy (damage to nerve production in bowel area so decrease movement)
Spinal cord injury or tumours
Cerebrovascular accident
Multiple sclerosis
Parkinsons
Connective tissue disorders
Hirschsprung’s disease
What mechanical problems of the anus/rectum can cause constipation?
Rectal prolapse
Poor thyroid function
Lead poisoning
Pregnancy
Travel
Immobility
What factors would you need to gather to get a wider diagnosis for constipation?
Medical history
History of symptoms:
-normal pattern
-other symptoms
-freq and consistency, faecal impaction, incontinence
-how long/ intense are the symptoms
-impact on daily life
Medications
Changes in diet/lifestyle :
-change in jobs
-holiday
-diet
What is the aetiology of constipation in children?
Prevalent in 5-30% of children
Aetiology often unknown, may be due to weening off breast milk
What are the symptoms of constipation in children?
Infrequent bowel activity
Foul smelling wind/stools
Excessive flatulence
Irregular stool texture
Abdominal pain, distension, discomfort
Soiling/over flow
What are the causes of constipation in older people?
Age related decline in GI motility, decrease in elasticity
Decreased mobility
Poor diet- low solid and liquid intake
Wasting of pelvic floor muscles
SEs of medication
Describe the Bristol stool chart:
Type 1/2 = constipation
separate hard lumps
Type 6/7 = diarrhoea
watery, no solid pieces
Aim for Type 4
Name examples of bulking agents:
Ispagula husk
Methylcellulose
Name examples of stimulant laxatives:
Bisacodyl (oral/rectal)
Senna
Dantron (co-danthrusate/ co-danthramer)
Sodium picosulfate
Name examples of faecal softeners:
Docusate (oral/rectal)
Glycerol (suppository)
Arachis oil (enema)
Name examples of osmotic laxatives:
Lactulose, macrogols (inert polymers of ethylene glycol)
MgOH and MgSulfate, phosphate (enema/suppository)
Sodium citrate (microenema)
How long does acute constipation last for?
Less than 4 weeks
What is the treatment plan for acute constipation?
Lifestyle advice and managing underlying causes
Bulk forming (1-3 days if insufficient response)
+/OR osmotic e.g macrogol (on its own if bulk isn’t working)
Stimulant
Gradually reduce and stop after producing soft, formed still without straining at least 3x a week
What is the treatment plan for chronic constipation?
Same as acute, but after everything else can try Prucalopride
Describe when prucalopride is used:
Used when 2 other laxatives have been used for max dose for at least 6 months
Prokinetic serotonin agonist which stimulates GI motility
What is faecal loading?
Build up of faecal matter within the colon
What is impaction?
Dry, hard stools as has been in the colon for a long while
What would be the first line treatment for impaction (hard stools) and how quick do they work?
High dose oral macrogol (48hrs max)
Stimulant (12hrs)
What would be the second line treatment for impaction if there was no initial response or slow?
Glycerol alone or glycerol +bisacodyl suppository (30 mins)
What would be the third line treatment for impaction if there was still an inadequate response?
Sodium phosphate (most powerful osmotic laxative) or arachis oil retention enema
What would be the first line treatment for faecal loading (soft stools) and how quickly do they work?
Stimulant (12hrs)
What would be the second line treatment for faecal loading if there was no initial response or slow?
Docusate or sodium citrate mini enema
What laxative would you not give in opioid induced constipation and why not?
Bulk forming laxative (antagonists)
MoA is to increase faecal mass causing colon to become distended leading to peristalsis, opioids decrease peristalsis
What would be the first line treatment for opioid induced constipation?
Osmotic laxative (or docusate) and a stimulant laxative
What would be the second line treatment for opioid induced constipation if first line unsuccessful and how does it work?
Naloxegol (oral)
Peripherally acting mu-opioid receptor antagonist (PAMORA)
They don’t antagonise the important central opioid receptors
What would be the third line treatment for opioid induced constipation if all unsuccessful?
Methylnaltrexone (sc)- PAMORA
Naldemedine (oral)
What would be some lifestyle advice to give to a patient if they have constipation?
High fibre diet
30g fibre a day with sufficient fluid
Caution in obstructive symptoms or fecal impaction
Ineffective in slow transit constipation or defecatory disorders
Switch from white to wholemeal
Increase physical activity
2L water per day (8 glasses)
What would be the guidelines for suggesting a laxative for a person who is pregnant and experiencing constipation?
Offer a bulk forming
Add or switch to an osmotic
Can consider a short course of stimulant such as Senna (NEVER close to term as can stimulate contractions and prescribed only)
Glycerol suppository
What would be the guidelines for suggesting a laxative for a person who is breastfeeding and experiencing constipation?
The same as pregnancy but can use bisacodyl or Senna and doesn’t need to be prescribed only
What would be the treatment steps for children with constipation?
1st- macrogols and negotiated and non punitive behaviour
2nd- add stimulant laxative
3rd- add lactulose (or other softening) if macrogol not tolerated
What are the considerations when looking at laxatives for children?
Some paediatric aren’t licensed for children under 2 so verbal onset documented needed
Suppositories and enemas not reccomened in primary care
What are the counselling points for ispagula husk?
1 sachet BD (12 years and over)
Sachets poor in a full glass of water and drink straight away
Take after meals, and not before bed as it encourages peristalsis and no peristalsis in sleep
Take 1/2 to 1 hr before/after other meds
Remains effective despite long term use
What is the strength and brand of Ispagula husk?
Fybogel 3.5g sahcets
High fibre is same as original
What are the counselling points for methylcellulose?
3-6 tabs BD with atleast 300ml of liquid
Break tabs in mouth before swallowing
Do not take just before bed
Ensure good fluid intake
2-3 days for effect
What is the strength and brand of methyl cellulose?
Celevac 500mg tabs
What are the counselling points for macrogol?
1-3 sachets daily, in divided doses
Sachets dissolve in 125ml of water
High in Na so CI in hypertension, heart disease and renal impairment
Don’t take other medicines an hour before or after
1-3 days for effect
What are the counselling points for lactulose?
15-45ml daily in single or divided doses
Very sweet tasting liquid
Can cause bloating or colic- caution if intolerant to lactose
No issue for diabetic patients as not absorbed through gut wall so no impact on sugar levels
Up to 2 days for effect
What are the counselling points for MgOH, Milk of Magnesia?
Mainly seen as liquid 30-45ml PRN
Take at bedtime
Can be abused (strong effect)
Old fashioned- caution in elderly
Commonly seen OTC, max 3 days
Around 3-6 hrs for effect
What are the counselling points for Docusate?
Up to 500mg daily in divided doses
12-72 hrs for effect of tabs, 15 mins for suppositories
Softening agent and stimulant
May be useful alternative for people who find it hard to increase fluid intake
Generally well tolerated
What are the brand names for docusate?
DulcoEase
Dioctyl
What are the counselling points for suppositories and enems?
Quick action, making it better, less likely for hospitalisation
Arachis oil enema contains peanut
Describe how you would insert a suppository:
Lay on left side- use a water soluble lubricant
Hold it between thumb and finger and put blunt edge into anus
Go to the depth of your finger
Lie still and hold for 10-15 mins
Describe how you would insert an enema:
Warm enema in bowl of warm water
Lay on left side and keep knees up to chest
Push nozzle in 3 inches
Squeeze contents in and hold for 5 mins, go to the toilet when needed
Stay near the toilet for the next hour
Some people have stomach cramps for a while and occasionally people feel faint and dizzy, lay down if this occurs
Why are stimulant laxatives for short term use only?
Work directly on SM of bowel promoting peristalsis and can cause lazy bowel
What are the counselling points for senna?
Senokot
Tabs and syrups 7.5-15mg daily (max 30mg)
Onset of action is 8-12 hours, take in evening for morning movement
Syrup is unpalatable
What are the counselling points of dantron?
Co-danthramer includes PEG
Co-danthrusate includes docusate
Colours urine red
Avoid prolonged contact with skin
Only in terminally ill patients (potential carcinogen)
Oral solution
Onset of action 6-12 hrs
What are the counselling points for sodium picosulphate and name the brand:
Dulcolax (liquid)
5-10mg OD
Tabs and syrup
Syrup is palatable
Onset of action 10-14 hrs
What are the counselling points for bisacodyl and name the brand:
Duclolax (tabs and suppositories)
Acts on SI
5-10mg OD, increase to 20mg OD if necessary
Tabs act in 10-12 hrs
Suppositories act in 20-60 mins
Suppositories can cause local inflammation
How does prucalopride work and when should it be prescribed?
A SS5HT4 receptor agonist with pro kinetic properties (promotes gut motility)
Should only be prescribed by clinicians experienced in treating constipation after careful review
What is the dosing of prucalopride and how long does it take to work?
2mg tabs OD, review treatment if no response after 4 weeks (reduce dose in elderly 1mg)
1-2 weeks for effect, increasing dose will not improve response
What are the side effects of prucalopride?
Headache
GI disturbances
What are bulk forming laxatives made of?
Mostly of plant origin, including non digestible polysaccharides including cellulose
What are the red flags of constipation?
Pain on defecation- causing suppression of reflex
Pt over 40 years with sudden change in bowel habits and no obvious cause
Greater than 14 days duration and no obvious cause
Associated fatigue
Presence of blood
Repeated failure of laxatives
Suspected laxative abuse
What is acute diarrhoea?
Abrupt onset of 3 or more loose stools a day and lasts no longer than 14 days
How does acute diarrhoea normally resolve?
Majority resolves in 2-3 days without specific treatment, just oral rehydration sachets
What is chronic diarrhoea?
Pathological cause which lasts more than 14 days, possible flare up of previously diagnosed condition
What is the pathophysiology of diarrhoea?
Change in the balance between absorption and secretion of water and electrolytes
What can be one reason to why the pathophysiology of diarrhoea occurs?
Osmotic force that drives water into the gut lumen e.g after ingestion of non absorbable sugars e.g xylitol, sorbitol, pancreatic insufficiency, cystic fibrosis
Proportional to the intake and responsive to fasting e.g can be avoided if don’t eat
What is another reason to why the pathophysiology of diarrhoea occurs?
Enterocytes actively secreting fluid e.g enterotoxin-induced diarrhoea
Not responsive to fasting
Ion transporters activated by e.g bacteria resulting in pathogens:
-invading enterocytes or
-producing enterotoxins (toxic to mucosal lining of GIT)
-induce cytokine secretion to produce PG which stimulates secretion of fluid and electrolytes
Describe the mechanism of invasive bacteria induced diarrhoea:
Directly attack mucosal cells with causes diarrhoea
Stools may contain blood/pus
Fever
e.g shingella, salmonella, Yersinia, Enterinvasive Ecoli