Gastrointestinal Flashcards
What is upper GI tract bleeding
A medical emergency
Involves some form of bleeding from the oesophagus, stomach or duodenum
What are the causes of upper GI bleeding
Oesophageal varices
Mallory-Weiss tear
Ulcers of the stomach or duodenum
Cancers of the stomach or duodenum
How does upper GI blleding present
Haematemesis (vomiting blood)
Coffee ground vomit (caused by vomiting digested blood that looks like coffee)
Melaena, which is tar like, black, greasy and offensive stools caused by digested blood
Haemodynamic and other signs of shock (young fit patients may compensate well until they have lost a lot of blood)
Symptoms related to underlying pathology:
-Epigastric pain and dyspepsia in peptic ulcers
-Jaundice for ascites in liver disease with oesophageal varices
What is the Glasgow-Blatchford score
A scoring system used in suspected upper GI bleed on initial presentation
It scores patients based on their clinical presentation
It establishes their risk of having an upper GI bleed to help managment planning
Using an online calculator is the easiest way to calculate the score. A score > 0 indicates high risk for an upper GI bleed. It takes into account various features indicating an upper GI bleed:
-Drop in Hb
-Rise in urea
-Blood pressure
-Heart rate
-Melaena
-Syncopy
What is the Rockall Score
Used for patients that have had an endoscopy to calculate risk of rebreeding and overall mortality
It provides a percentage risk of rebleeding and mortality
Use an online calculator
Takes in to account these risk factors:
-Age
-Features of shock (e.g. tachycardia or hypotension)
-Co-morbidities
-Cause of bleeding (e.g. Mallory-Weiss tear or malignancy)
-Endoscopic stigmata of recent haemorrhage such as clots or visible bleeding vessels
How is an upper GI bleed managed
A – ABCDE approach to immediate resuscitation
B – Bloods
– Haemoglobin (FBC)
– Urea (U&Es)
– Coagulation (INR, FBC for platelets)
– Liver disease (LFTs)
– Crossmatch 2 units of blood
A – Access (ideally 2 large bore cannula)
T – Transfuse
– Transfuse blood, platelets and clotting factors (fresh frozen plasma) to patients with massive haemorrhage
– Transfusing more blood than necessary can be harmful
– Platelets should be given in active bleeding and thrombocytopenia (platelets < 50)
– Prothrombin complex concentrate can be given to patients taking warfarin that are actively bleeding
E – Endoscopy (arrange urgent endoscopy within 24 hours)
D – Drugs (stop anticoagulants and NSAIDs)
There are some additional steps if oesophageal varices are suspected, for example in patients with a history of chronic liver disease:
-Terlipressin
-Prophylactic broad spectrum antibiotics
The definitive treatment is oesophagogastroduodenoscopy (OGD) to provide interventions that stop the bleeding, for example banding of varices or cauterisation of the bleeding vessel.
NICE recommend against using a proton pump inhibitor prior to endoscopy, however you may find senior doctors that do this.
What is constipation
A common complaint that refers to the infrequent passage of stool, difficulty passing stool and/or a sensation of incomplete emptying of bowels
What are the two types of constipation
Primary:
-in the absence of an underlying cause
-aka functional or idiopathic
Secondary:
-due to an underlying pathology (eg. meds, GI disorder, endocrine disorder etc)
What are the sub types of primary constipation
Normal transit constipation: infrequent defaecation with evidence of normal colonic transit (most common)
Slow transit constipation: infrequent defaecation with evidence of slow colonic transit
Dyssynergic defecation: an inability to empty the rectum effectively. Due to paradoxical contraction or inadequate relaxation of pelvic floor muscles during defecation
What are the common causes of secondary constipation
Neurological: Parkinson’s disease, Hirschsprung disease, spinal cord injury, multiple sclerosis
Metabolic: Hypercalcaemia, diabetes mellitus, hypokalaemia
Endocrine: Panhypopituitarism, hypothyroidism
Medications: Iron supplements, antispasmodics, calcium-channel blockers, opiates, tricyclic antidepressants
Rheumatological: Systemic sclerosis, myotonic dystrophy, amyloid
Gastrointestinal: Irritable bowel syndrome, colonic strictures, inflammatory bowel disease, rectal prolapse
Pregnancy
What is faecal impaction
The retention of faeces in the rectum and colon to the extent that spontaneous evacuation is unlikely.
It may complicate a primary or secondary cause of constipation.
It is usually diagnosed on digital rectal examination or noted on imaging.
What is normal colonic function
The primary function of the colon is to absorb water and transport waste from the caecum to the rectum for evacuation. Colonic motility is important for the transport of faeces to the rectum where distension initiates the urge to defaecate. Defecation then relies on the coordinated relaxation of the internal anal sphincter and pelvic floor muscles with contraction of the diaphragm and abdominal muscles.
What are the types of colonic motility
Segmental activity: repetitive non-propulsive contractions that aid mixing and absorption
Propagated activity:
-large, coordinated contractions that aid the propulsion of stool from caecum to rectum.
-Divided into ‘low-amplitude propagated contractions (LAPC)’ and ‘high-amplitude propagated contractions (HAPC)’.
-LAPCs are frequent, low amplitude, and help transport content in the colon.
-HAPCs are less frequent, have high amplitude and act as powerful contractions involved in defecation itself.
What is the gastrocolic reflex
The association between eating and the urge to defecate
How does defecation happen
The initial part of defecation involves rectal filling. This activates receptors in the rectal wall that results in conscious awareness of needing to defecate. A small amount of faeces enters the anal canal by an involuntary relaxation of the internal anal sphincter. This is the rectoanal inhibitory reflex. If it is deemed socially acceptable to defecate, the person will find a toilet and adopt a sitting or squatting position. If not socially acceptable the rectal wall relaxes and the need to defecate subsides temporarily. During defecation, contraction of the abdominal muscles and diaphragm help to exert pressure on the abdominal viscera. At the same time, coordinated relaxation of the external anal sphincter and puborectalis helps to evacuate faeces down the created pressure gradient. After evacuation, there is a closing reflex with regaining external anal sphincter tone.
How is normal faecal continence maintained
The internal and external anal sphincters remain contracted.
In addition, a sling of muscle known as the puborectalis, which is part of the pelvic floor, tethers the rectum forming a tight angle that acts as a barrier to faeces entering the anus.
What are the Clinical features of constipation
Characterised by infrequent bowel motions, hard lumpy stools, straining, and incomplete emptying.
Infrequent stools are broadly defined as < 3 spontaneous bowel motions per week.
Symptoms
-Infrequent bowel motions
-Hard, lumpy stool
-Straining
-Manually extracting faeces
-Overflow diarrhoea (liquid stool leak around stool)
-Overflow incontinence (loss of control of defecation)
-Feeling incomplete emptying
Exam may show signs of secondary cause.
Examine abdomine
Nutritional status observation
PR exam to exclude structural problem and stength of sphincter function and defecation mechanism
What are the red flag symptoms of constipation
Weight loss
Rectal bleeding
Family history of colorectal cancer
Sudden change in bowel habit
Abdominal pain
Iron deficiency anaemia
What is the Rome IV criteria
Diagnosis of chronic idiopathic constipation
Must include two or more of the following:
-Straining during more than 25% of defecations
-Lumpy or hard stools (Bristol Stool Form Scale 1-2) more than 25% of defecations
-Sensation of incomplete evacuation more than 25% of defecations
-Sensation of anorectal obstruction/blockage more than 25% of defecations
-Manual maneuvers to facilitate more than 25% of defecations (e.g., digital evacuation)
-Fewer than three spontaneous bowel movements per week
-Loose stools are rarely present without the use of laxatives
-Insufficient criteria for irritable bowel syndrome
-The criteria must be fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis.
What are FDDs
Functional defecation disorders
The patient must satisfy diagnostic criteria for chronic idiopathic constipation and/or irritable bowel syndrome with constipation
During repeated attempts to defecate, there must be features of impaired evacuation, as demonstrated by 2 of the following 3 tests:
-Abnormal balloon expulsion test
-Abnormal anorectal evacuation pattern with manometry or anal surface electromyography (EMG)
-Impaired rectal evacuation by imaging
The criteria must be fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis.
FDDs may be subcategorised as dyssynergic defecation if there is an inappropriate contraction of the pelvic floor as measured with anal surface EMG or manometry with adequate propulsive forces during attempted defecation. The measurement of pelvic floor contraction is done through specialist anorectal physiology testing.
How is constipation investigated
Most people do not require extensive investigation
Exclude secondary causes
Investigate red flag features
Investiagte when refractory to initial therapy
Stool tests:
For ?IBD or ?colorectal cancer
-Faecal calprotectin (FCP)
-Quantitative faecal immunochemical test (qFIT)
Bloods:
To exclude secondary causes or to look for red flag features (eg thyroid problems or anaemia)
-Full blood count
-Renal profile
-Bone profile
-HbA1c
-Thyroid function tests
-Specialist: parathyroid hormone, cortisol, electrophoresis
Imaging:
-reserved for pts with a suspected secondary cause of constipation (eg diverticular stricture, malignancy)
-CT abdomen and pelvis
-MRI pelvis
-Abdominal xray (incidental findings of constipation)
Endoscopy:
-Colonoscopy in pts with new change of bowel habit to exclude sinister causes
-Recommended in pts with red flag features
– Age > 50 with unexplained rectal bleeding
– Age > 50 with rectal bleeding and change in bowel habit
– Age > 60 with change in bowel habits
Specialist investigations:
-In severe, refractory constipation that will be guided by gastroenterologists
-Colonic transit studies: use of radiopaque markers to assess colonic transit.
-Wireless motility capsule: ingestion of a wireless capsule to assess regional or whole gut transit time
-Defecography: assesses a patient evacuating barium solution to investigate structural problems contributing to defecatory disorders. A defecatory MRI proctogram is commonly requested
-Anorectal physiology: a series of investigations that can be used to assess sphincter function, rectal sensitivity, propulsive function, pressures (i.e. manometry), and ability to expel a balloon (simple form of defecography)
How is constipation managed
Most patients can be managed with simple lifestyle modifications or basic laxatives.
Address any secondary factors that have precipitated constipation.
The general treatment approach should be:
-Lifestyle modifications
-First-line laxatives (osmotic, bulk-forming, softeners)
-Second-line laxatives (stimulants, suppositories and/or enemas)
-Consider biofeedback (defecatory disorders)
-Newer therapies (prokinetics, secretagogues)
-Interventional treatments
What are the lifestyle modifications which can help manage contipation
Eat a healthy diet that is high in whole grains, fruit and vegetables
Slowly increase fibre in diet to 30g/day (too fast can lead to flatulence and bloating)
Maintain good fluid intake to avoid dehydration
Take regular exercise
Basic toilet regimens can be advised:
-Regular, unhurried routine to ensure complete defecation
-Respond immediately to sensation to defecate
-If limited mobility, ensure appropriate access to toilets and privacy
-Provide supported seating if unsteady on toilet
What are the types of laxatives available
Bulk forming laxative -> addition of osmotic laxative -> second line (stimulants) -> rectal therapies
The different types of laxatives include:
Bulk-forming (e.g. fybogel - ispaghula husk, methylcellulose):
-increase the ‘bulk’ of the stool that stimulates bowel function.
-usually take 2-3 days to work
-first line.
-important to drink plenty of water alongside bulk laxatives.
Osmotic (e.g. macrogol, lactulose):
-poorly absorbable molecules that exert an osmotic effect drawing water into the bowel lumen.
-very commonly used laxatives
-offered after bulk-forming laxatives.
-very effective in faecal impaction and infrequent bowel motions.
Stimulant (e.g. senna, bisacodyl, sodium picosulfate):
-stimulate the local nervous system within the gut wall that increases colonic contractility and secretions.
-work in 6-12 hours.
-may be used second-line
-better for patients with difficulty emptying rather than infrequent motions.
Softeners (e.g. arachis oil, sodium docusate):
-Docusate lowers the surface tension, which leads to water and fats penetrating the stool.
-typically combined with other laxatives (e.g. stimulants).
Suppositories (e.g. glycerol, bisacodyl):
-can be used to aid rectal emptying by stimulating the anal sphincter and initiating peristalsis.
-Glycerol is an osmotic type laxative
-Bisacodyl is a stimulant.
-May be combined with oral laxatives.
-Commonly used if inadequate response to oral, incomplete emptying, incontinence, or altered rectal sensitivity.
-Cause more rapid evacuation
Enemas (e.g. phosphate, sodium citrate, docusate):
-include osmotic, softeners, and/or weak stimulants.
-A phosphate enema contains 128 mL of liquid whereas others are ‘mini-enemas’ that come as only 5 mL.
-These can be combined with oral laxatives as needed.
-Like suppositories, they act quickly to bring about a more rapid evacuation.
What are the newer therapies being used in constipation management
Typically offered in ongoing contipation despite use of two conventional laxatives from two different classes for at least 6 months
Prokinetics (e.g. Prucalopride):
-Prucalopride is commonly used that works as a selective serotonin 5-HT4 receptor agonist.
-It simulates mass colonic movement and has an action on other areas of the gastrointestinal tract.
-It is contraindicated in colonic obstruction and should be used with caution in patients with ischaemic heart disease.
Secretagogues (e.g. Linaclotide, Lubiprostone):
-work by increasing intestinal chloride secretion that is associated with increased water secretion into the bowel lumen.
-Linaclotide activates the secretion of chloride through guanylcyclase C which activates CFTR chloride channels.
-Lubiprostone is derived from prostaglandin E1 and directly activates chloride channels and CFTR.
-Lubiprostone has been withdrawn in the UK market.
Opioid-antagonists (e.g. Naloxegol):
-Naloxegol is a peripherally acting opioid receptor antagonist.
-It decreases the constipating effects of opioids without altering their central analgesic effects.
How is faecal impaction treated
Typical regimen of high-dose macrogol which is an osmotic laxative
If there has been an inadequate response then macrogol can be combined with suppositories or enemas
After a few days of an osmotic laxative, or if stools are soft, a stimulant laxative can be used (avoid if stools are hard)
What is anorectal biofeedback
A treatment for patients with constipation related to disordered defecation or those with faecal incontinence.
It involves providing the patient with coaching and visual cues to help assist them with isolating and coordinating the pelvic floor muscles during defecation.
Anorectal biofeedback is run by experienced bowel nurse specialists and can be completed with or without the use of anorectal physiology. It essentially helps patients to strengthen or relax the pelvic floor muscles during defecation.
What are the surgical interventions for constipation
Rarely needed
In severe cases, surgical intervention may be offered (eg. subtotal colectomy, segmental colectomy, STARR procedure)
Mechanism behind contipation is important to determine to decide appropriate surgical intervention
Need to exclude gastrointestinal dysmotility that responds poorly to surgery.
What is diarrhoea
The passage of loose/ watery stool at least 3 times per 24hrs
How diarrhoea classified
Classification based on duration:
-Acute: <2 weeks
-Sub-acute: 2-4 weeks
-Chronic: >4 weeks
Classification based on etiology: mainly for acute
-Community acquired
-Hospital-acquired
What are the differentials for diarrhoea
GI:
-Infection
– gastroenteritis
– tropical infections
-Inflammation
– IBD
– diverticulitis
-Coeliac disease
-Lactose intolerance
-Colorectal carcinoma
-IBS
-Overflow
Endocrine:
-Thyroxicosis
-Addison’s
Drugs:
-Antibiotics
-PPIs
-Metformin
-Laxatives
-Digoxin
-Propanolol
-Alcohol
How is diarrhoea investigated
Extent of investigations depends on symptoms severity, chronicity, and red flags
Bloods:
-FBC
-U and Es
-LFTs
-TFTs
-Calcium
-Inflammatory markers
-Coeliac serology
-Faecal calprotectin
Stool:
-MC+S
-C.diff toxin
-Ova and parasites
-Faecal elastase (chronic pancreatitis)
-Gut hormones (gastronome, VIPoma)
Breath:
-13C breath test (H.pylori)
-Hydrogen breath test (lactose intolerance)
Endoscopy
How is diarrhoea managed
Usually spontaneously resolves
Manage underlying causes
Oral rehydration solution or IV fluids if severe dehydration
Consider loperamide
What is loperimide
u-opioid receptor agonist in the myenteric plexus, reducing smooth muscle tone
Doesn’t cross blood brain barrier so no CNS effects
Indications:
-Watery diarrhoea that interferes with daily function
-IBS
-Traveller’s diarrhoea
What is malnutrition
A sudden or chronic decrease in the intake of sufficient nutrition to support the body’s requirements for growth, healing and maintenance of life
Estimated that over 30% of patients admitted to hospital will experience a form of malnutrition
What is acute malnutrition
A brief period of inadequate nutrition that is most commonly in relation to an acute illness with a high inflammatory state and results in muscle wasting and rapid weight loss
What is chronic malnutrition
Inadequate nutrition that lasts longer than 3 months
Often secodnary to social, behavioural and economic factors in addition to illness related causes
What screening tools can be used for assessing malnutrition
Malnutrition Univeral Screening Tool (MUST)
Malnutrition Screening Tool (MST)
Mini-nutrtion Assessment (MNA)
What is the aetiology for malnutrition
As metabolic demand increase due to illness, injury or stressors such as exercise, people adapt their nutritional intake to meet the body’s requirements.
In settings of chronic disease and certain drugs, this normal course of adaptation because difficult and can lead to acute or chronic malnutrition
Three main reasons people may become malnourished:
-Inadequate amounts of nutrients (e.g. poor variety in diet)
-Difficulty absorbing nutrients (e.g. gastrointestinal dysfunction such as coeliac disease)
-Increased nutritional demands (e.g. post-surgery for healing)
What are the risk factors for malnutrition
Highest risk:
-those with chronic illnesses
-the elderly
-those living in supported accommodation
-patients drinking excessive amounts of alcohol over a prolonged period.
Other risk factors for malnutrition include:
-Being hospitalised for extended periods of time
-Problems with dentition, taste or smell
-Polypharmacy
-Social isolation and loneliness
-Mental health issues including grief, anxiety and depression
-Cognitive issues including confusion
What are the clinical features of malnutrition
-High susceptibility or long durations of infections
-Slow or poor wound healing
-Altered vital signs including bradycardia, hypotension, and hypothermia
-Depleted subcutaneous fat stores
-Low skeletal muscle mass
In children, other indicators are:
-Wasting: low weight for height
-Stunting: low height for age
-Underweight: low weight for age
What is the significance of serum albumin levels in malnutrition
Hypoalbuminaemia occurs in conditions where there is an excessive amount of protein being lost or where the production of albumin is impaired
Can also occur in the context of inflammatory states such as infections
Serum albumin should not be relied on in isolation to assess a patient’s nutritional state as there are a wide variety of factors which influence levels
What are the important areas to cover in malnutrition history taking
Weight history:
-current weight
-recent changes to weight
-changes to fit of clothes
Meal history:
-regularity of meals including skipping meals
Protein intake:
-intake of high-quality protein
Hydration:
-intake of fluids
How is a patient with suspected malnutrition examined clinically
Weight:
-unexpected weight loss from someone’s normal weight is indicative of a period of malnutrition.
-This includes people who are clinically overweight and obese.
Body mass index (BMI):
-a patient’s BMI indicates whether they might be malnourished.
-It is not however as accurate as history and clinical examination, and should never be used in isolation.
Review of muscle mass stores
Review of subcutaneous fat stores
Consideration could also be given to measuring:
-a patient’s grip strength
-triceps skin fold thickness
-mid-arm muscle circumference
How is malnutrition managed
Consideration of patients goals of care, prognosis and social factors
Dietician involvement
Treat reversible causes (eg infection or inflammatory state)
Oral nutrition used as long as possible with use of oralnutritional support such as high-energy-high-protein supplements and fortified food products
Minor changes to diet can have significant positive impact on patient’s nutritional status
If unable to safely swallow or unable to take sufficient calories orally, NG feeding should be considered.
For long term feeding, a gastrostomy (PEG or RIG) or jejunostomy should be considered
Parenteral nutrtion should be reserved for patients with intestinal failure or inaccessible givestive tracts
What is refeeding syndrome
A condition caused by rapid re-introduction of normal nutrition in patients who are chronically malnourished
In chronic malnutrition, a patient’s intracellular stores of key electrolytes become depleted.
If a patient then is suddenly provided with normal levels of nutrition, there is a sudden shift of these electrolytes from the extracellular to the intracellular compartment driven by a large insulin response and other factors.
Can ultimately lead to a sudden drop in extracellular levels of key electrolytes resulting in hypokalaemia and hypophosphataemia
This can subsequently lead to cardiac complications (eg arrhythmias)and seizures
How is refeeding syndrome prevented
Nutrition is re-introduced more gradually under the guidance of a dietician and the patients electrolytes are monitored closely, allowing deficiencies to be identified early and replaced appropriately
What are the potential complications of malnutrition
Impaired immunity (increased risk of infections)
Poor wound healing
Growth restriction in children
Unintentional weight loss, specifically the loss of muscle mass
Multi-organ failure
Death
What is GORD
Gastro-oesophageal reflux disease
Where acid from the stomach refluxes through the lower oesophageal sphincter and irritates the lining of the oesophagus
The oesophagis has a squamous epithelial lining making it more sensitive to the effects of stomach acid compared to the stomach which has columnar epithelial lining, which is more protected against stomach acid
How does GORD present
Dyspepsia
Heartburn
Acid regurgitation
Retrosternal or epigastric pain
Bloating
Nocturnal cough
Hoarse voice
What are the red flag symptoms which indicate referral for endoscopy in a reflux type picture
Dysphagia (difficulty swallowing) at any age gets a two week wait referral
Aged over 55 (this is generally the cut off for urgent versus routine referrals)
Weight loss
Upper abdominal pain / reflux
Treatment resistant dyspepsia
Nausea and vomiting
Low haemoglobin
Raised platelet count
How is GORD managed
Lifestyle advice
-Reduce tea, coffee and alcohol
-Weight loss
-Avoid smoking
-Smaller, lighter meals
-Avoid heavy meals before bed time
-Stay upright after meals rather than lying flat
Acid neutralising medication when required:
-Gaviscon
-Rennie
Proton pump inhibitors (reduce acid secretion in the stomach)
-Omeprazole
-Lansoprazole
Ranitidine
-This is an alternative to PPIs
-H2 receptor antagonist (antihistamine)
-Reduces stomach acid
Surgery
-laparoscopic fundoplication.
-involves tying the fundus of the stomach around the lower oesophagus to narrow the lower oesophageal sphincter.
What is H.pylori
H. pylori is a gram negative aerobic bacteria.
It lives in the stomach.
It causes damage the epithelial lining of the stomach resulting in gastritis, ulcers and increasing the risk of stomach cancer.
It avoids the acidic environment by forcing its way into the gastric mucosa.
The breaks it creates in the mucosa exposes the epithelial cells underneath to acid.
It also produces ammonia to neutralise the stomach acid.
The ammonia directly damages the epithelial cells.
Other chemicals produced by the bacteria also damage the epithelial lining.
How is H.pylori tested for
Offer a test for H. pylori to anyone with dyspepsia.
They need 2 weeks without using a PPI before testing for H. pylori for an accurate result.
Tests
-Urea breath test using radiolabelled carbon 13
-Stool antigen test
-Rapid urease test can be performed during endoscopy.
– A rapid urease test is also known as a CLO test (Campylobacter-like organism test).
– It is performed during endoscopy and involves taking a small biopsy of the stomach mucosa.
– Urea is added to this sample.
– If H. pylori are present, they produce urease enzymes that converts the urea to ammonia.
– The ammonia makes the solution more alkali giving a positive result on when the pH is tested.
How is H.pylori eradicated
The eradication regime involves triple therapy with a proton pump inhibitor (e.g. omeprazole) plus 2 antibiotics (e.g. amoxicillin and clarithromycin) for 7 days.
The urea breath test can be used as a test of eradication after treatment. This is not routinely necessary.
