Gastroenterology Flashcards
What is Peptic Ulcer disease?
A surface breach of the mucosal lining of the GI tract, occurring as a result of acid and pepsin attack
What is the stool volume in secretory diarrhoea?
Very large
What is odynophagia?
Painful swallowing
At what level does the superior mesenteric artery arise from the abdominal aorta?
L1 vertebra
Which artery supplies the jejenum and ileum?
Superior mesenteric artery
What can untreated GORD lead to?
Barretts oesophagus
Name two IBD.
Crohns disease
Ulcerative colitis
What are the parasympathetic fibres of the stomach?
Gastric branches of the left and right vagus nerves
From what does the stomach get sympathetic innervation?
Splanchnic nerves
Coeliac ganglion
What is the ion gap in secretory diarrhoea?
Less than 100mOsm/kg
What is the most common cause of PUD?
H. pylori infection
What are the four layers of the gut?
Mucosa
Submucosa
Muscularis externa
Serosa
What are the three types of diarrhoea?
Osmotic
Secretory
Inflammatory
What is inflammatory diarrhoea?
Diarrhoea occurring when there is damage to the mucosal lining or brush border, leading to passive loss of protein-rich fluids and decrease ability to absorb lost fluids
Name a possible cause of inflammatory diarrhoea.
IBD
Infections
What is secretory diarrhoea?
Diarrhoea due to an increase in active secretion or an inhibition of absorption
Name a possible cause of secretory diarrhoea.
Cholera toxin - stimulates secretion of anions, especially chloride ions
Name symptoms of GORD.
Heartburn Acid reflux Dysphagia Chest pain Water brash Odynophagia Nausea
What happens to osmotic diarrhoea in response to fasting?
It stops
What happens to secretory diarrhoea in response to fasting?
The diarrhoea continues
What is the main cause of steattorrhoea?
Name something that can cause it.
Malabsorption of fat
Pancreatic disease or Coeliac disease
What is osmotic diarrhoea?
Water is drawn into the bowels resulting in watery stool
Name a possible cause of osmotic diarrhoea.
Maldigestive cause such as coeliac disease
What is GORD?
Symptoms of mucosal damage produced by the abnormal reflux of gastric contents into the oesophagus
What is the ion gap in osmotic diarrhoea?
More than 100mOsm/kg
What are the symptoms of giardiasis?
Steatthorrea
Normally associated with recent travel, for example India
What bacteria can cause traveller’s diarrhoea?
ETEC - Enterotoxigenic Escherichia coli
What can sometimes precipitate a C. diff infection?
Antibiotic treatment
What types of drugs neutralise stomach acid?
Antacids
Name two side effects of alginates and which two products cause them.
Constipation (aluminium)
Diarrhoea (magnesium)
What is the mechanism of action of sucralfate and misoprostol?
Promote mucosal defense
Name side effects of sucralfate.
Constipation Reduction in absorption of some drugs Nausea Dry mouth Bezoar formation Vomiting Headaches Rashes
How does misoprostol work?
Binds to prostaglandin receptors on parietal cells causing a negative feedback on the proton pump
What is the most common adverse effect of misoprostol?
Diarrhoea
Why is misoprostol contraindicated in pregnant women and women of child-bearing age?
Can cause partial or complete abortions (due to being PGE1 analog)
Can cause birth defects
What drugs can cause gastric ulceration?
NSAIDs
What are metoclopramide and domperidone’s mechanism of action?
Gastric stimulants (increase food transit through stomach) Act as D2 receptor antagonists
What class of drug inhibit histamine actions at H2 receptors?
H2 receptor antagonists: Ranitidine Cimetidine Nizatidine Famotidine
What effect do H2 receptor antagonists have?
Inhibit gastric secretion
What does PPI stand for and give examples of them.
Proton pump inhibitor: Omeprazole Lansoprazole Pantoprazole Esomeprazole
How do PPIs work?
Irreversibly inhibit action of proton pump, reducing both basal and stimulated gastric acid secretion
Although uncommon, what are some side effects of PPIs?
Headaches
Diarrhoea
Rashes
What are some adverse side effects of PPIs?
Pneumonia Increased risk of C. diff infection Rebound acid hypersecretion (if drugs stopped) Increased risk of fracture Drug interactions
Which bacterial infection is associated with development of gastric and duodenal ulcers and gastric cancers?
H. pylori
Name two viruses that may cause diarrhoea.
Rotavirus
Norovirus
What is the most likely cause of diarrhoea in a patient who is or has recently been in hospital?
C. diff infection
What causes pernicious anaemia?
Reduction in vitamin B 12 absorption
Which cells in the stomach produce gastrin?
G cells
Which cells are stimulated by gastrin?
Chief cells
Parietal cells
Which cells secrete somatostatin and what is its action?
D cells
Inhibit gastrin release
Where are G cells found?
Gastric pits of pyloric antrum
Where are chief cells primarily found and what do they produce?
Near base of gland
Secrete pepsinogen
Where are parietal cells found and what do they secrete?
Proximal portion of gland
Secrete hydrochloric acid (H+ via proton pump with Cl-) and intrinsic factor
What does intrinsic factor do?
Aids in absorption of B12
What are the associated symptoms of dyspepsia that can increase cancer risk?
Anaemia Loss of weight Anorexia/vomiting Recent progressive symptoms Melaena/haematemesis
What do prostaglandins regulate in the stomach?
Release of bicarbonate and mucous
Maintain mucosal blood flow
In a patient with GORD and ‘alarm’ symptoms, how would you investigate?
Gastroscopy
Barium swallow
What is 24-hour intraluminal pH monitoring reserved for?
Confirmation of GORD prior to surgery or in difficult diagnostic cases
What would a barium swallow show the presence of?
Hiatus hernia
Motility disorders
When would a plain abdomen X-ray be used?
Investigation of acute abdomen or acute colitis
Which abdominal organs is ultrasound a first-line investigation for?
Liver
Gall-bladder
Spleen
Pancreas
What non-invasive tests are used to investigate H. pylori infection?
Urea breath test
Serological tests to detect H. pylori IgG antibodies
Stool tests
How would you treat H. pylori infection?
PPI plus metronidazole and clarithromycin; or
PPI plus amoxicillin and clarithromycin
(all twice daily for a week)
How should you investigate a patient over 60 years with ulcer-type symptoms and why?
Endoscopy
To rule out gastric cancer
In an acute upper GI bleed what is your first choice of investigation?
Endoscopy
In a lower GI bleed what investigations could you do to determine the site of bleeding?
Rectal examination Proctoscopy Sigmoidoscopy Barium enema Colonoscopy Angiography
What is Meckel’s diverticulum?
Congenital abnormality where a diverticulum projects from the wall of the ileum
What is Crohn’s disease characterised by?
Skip lesions
Affect whole thickness of bowel wall
Granulomatous nature
What is characteristic of Ulcerative colitis?
Only mucosal layer affected of rectum +/- colon
Continuous distribution
Non-granulomatous nature
What produces the cobblestone appearance in CD?
Deep ulcers and fissures in mucosa
What are risk factors for CD?
Genetics
Diet
Smoking
Female
What is a protective factor for UC?
Smoking
What is the immune response mediated by in CD?
Th1 cells and macrophages (cell mediated immunity)
What is the immune response mediated by in UC?
Th2 and B cells (humoral immunity)
What part of the GIT is most commonly affected in CD?
Terminal ileum
What investigations would you do for suspected CD?
Bloods (FBC, Inflammatory markers, Antibody serology)
Barium follow through
Colonoscopy
How would you investigate a suspected UC?
Stool examination (microbiology) Bloods (FBC, Inflammatory markers, U&Es, LFTs) Abdo X-ray Endoscopy (colonoscopy)
What are the possible complications of UC?
Primary sclerosing cholangitis
Bowel cancer
Toxic megacolon
What is first line short term drug treatment for IBD?
Glucoorticoids - Prednisolone
What medication is used to maintain remission in IBD?
5-ASA drugs - e.g. mesalazine, olsazine
What immunosuppressant can be used for treatment of UC?
Ciclosporin
What immunosuppressant can be used for treatment in CD?
Methotrexate
What would severe pain occurring after meals, with less frequent relief by antacids or food be indicative of?
Gastric ulcer
What would epigastric discomfort, with pain radiating to the back, 2-5 hours after eating or when hungry, with burning and hunger-like pains be a sign of?
Duodenal ulcer
What is the most common functional bowel disorder?
Irritable bowel syndrome
What are some symptoms of IBS?
Nausea and vomiting
Bowel urgency
Abdo pain and bloating
Mucus in stool
What does the Rome III diagnostic criteria state a patient must have to be diagnosed with IBS?
In preceding 3 months, at least 3 days per month of recurrent abdo pain or discomfort, associated with at least 2 of following:
Improvement with defecation
Onset associated with change in frequency in stool
Onset associated with change in form of stool
What are the main three subtypes of IBS?
IBS with constipation
IBS with diarrhoea
Mixed IBS
Which are the most common subtypes of IBS?
IBS with constipation or mixed IBS
What are the three classified subgroups of constipation with a normal colon diameter?
Normal transit constipation
Slow transit constipation
Disordered defecation
What symptoms are associated with slow transit constipation?
Bloating
Abdo pain
Infrequent urge to defecate
In which patient is slow transit constipation most common?
Young women, with symptoms dating back to childhood
What is disordered defecation usually due to?
Rectal redundancy caused by: Pelvic floor dysfunction Anal sphincter dysfunction Structural abnormality (eg rectocele)
What is severe constipation with gut dilatation normally secondary to?
Neuromuscular disorder of the colon:
Hirschsprung’s disease
Idiopathic mega colon
Chronic intestinal pseudo-obstruction
What is Hirschsprung’s disease?
Congenital anganglionosis of colon, resulting in absence of anorectal reflexes
What are the main complications of idiopathic megarectum/megacolon?
Faecal impaction
Overflow incontinence
How are the findings on an abdominal contrast study different between Hirschsprung’s disease and idiopathic megarectum?
Hirschsprung’s - colon proximal to narrowing is dilated
Megarectum - colon distal to narrowing shows continuous dilatation until point of narrowing
In presence of constipation what diagnosis would anaemia suggest?
Colon cancer
What does an evacuation proctography show?
Anorectal morphology
Functional abnormalities - eg incoordination of pelvic floor and anal sphincters
Structural abnormalities - eg intussusception, rectal prolapse or rectocele
What is a useful method of measuring motor function of the whole gut?
Radio-opaque marker study of whole gut transit
What diagnosis does the presence of a recto-anal inhibitory reflex exclude?
Hirschsprung’s disease
What might an ano-rectal sensory test show?
Loss of rectal sensation, seen in MS and Parkinson’s
What diet advice is given to patients with constipation?
Increased fibre intake
Increased liquid intake
Name some stimulant laxatives and when would they be used?
Senna or bisacodyl As required (to prevent laxative dependence)
What are some osmotic laxative agents and when are they used?
Magnesium salts and lactulose
Effective in slow transit constipation
How do bulk-forming laxatives work?
Retain fluid within stool, increasing faecal mass
Stimulate peristalsis
Stool-softening properties
What is the order of treatment for short duration constipation in adults?
1st line - bulk forming laxative
2nd - add/switch to osmotic laxative
3rd - if stools are soft, but still finds difficult to pass, add stimulant laxative
What is in probiotics used for treating IBS?
Bifidobacterium
What is prucalopride?
Selective serotonin receptor agonist, acting on serotonin releasing enteroendocrine cells
What are antispasmodics used in chronic constipation?
Anticholinergic agents
Antimuscarinic agents
Peppermint oil
What can be used for pain management in chronic constipation?
Antidepressants, eg fluoxetine, paroxetine, citalopram
What are the surgical options for constipation caused by dysmotility?
Colectomy
Ileorectal anastomosis
Sacral nerve stimulation
Antegrade colonic enema
What does sacral nerve stimulation involve?
Implantation of programmable stimulator subcutaneously, which delivers low amplitude electrical stimulation via a lead to sacral nerve
What does the antegrade colonic enema (ACE) procedure involve?
Surgical creation of stoma, which functions as irrigation port to introduce fluid to wash out colon at regular intervals
What are surgical indications for treatment of obstructed defecation syndrome?
External prolapse
Rectocele
Internal intussusception
