Gastroenterology Flashcards
What is the mechanism of action of omeprazole?
It inhibits the action of H+/K+-ATPase, which is found in parietal cells.
What are the roles of vitamin B12 in the body?
- Red blood cell development
- Maintenance of the nervous system
What is the most common cause of vitamin B12 deficiency?
Pernicious anaemia
What are the causes of vitamin B12 deficiency?
- Pernicious anaemia
- Post gastrectomy
- Vegan diet/poor diet
- Disorders or surgery at the terminal ileum e.g. Crohn’s
- Metformin (rare)
What are the features of vitamin B12 deficiency?
- Macrocytic anaemia
- Sore tongue and mouth
- Neurological symptoms (ataxic gait, paraesthesia i.e. pins and needles)
- Neuropsychiatric symptoms (e.g. mood disturbances)
What is the management of vitamin B12 deficiency with no neurological involvement?
1 mg of IM hydroxocobalamin 3 times each week for 2 weeks, then once every 3 months
What are good sources of vitamin B12?
Meat, fish and milk
What is Barrett’s oesophagus?
Metaplasia of the lower oesophageal mucosa - squamous epithelium being replaced by columnar epithelium.
What is the increased risk of oesophageal adenocarcinoma in a patient with Barrett’s oesophagus?
50-100 fold
What is dyspepsia?
Indigestion
What are the symptoms of dyspepsia?
- Heartburn
- Bloating
- Nausea
- Burping and farting
- Bringing up food or fluids into your mouth
All occurs after eating
What is the difference between long and short Barrett’s oesophagus?
Short = <3cm
Long = >3cm
What cells need to be present along with metaplasia in order to diagnose Barrett’s oesophagus?
Goblet cells
What is Gilbert’s syndrome?
An autosomal recessive syndrome (mutation in UGt1A1 gene) caused by defective bilirubin conjugation as a result of a deficiency of UDP glucuronosyltransferase (UGT1A1 enzyme).
What are the features of Gilbert’s syndrome?
- Unconjugated hyperbilirubinaemia (too much bilirubin in the blood)
- Jaundice after illness, exercise or fasting (physiological stress)
What is Grey Turner’s sign?
Blue discolouration of the flanks indicating retroperitoneal haemorrhage
List the retroperitoneal structures:
- Duodenum (2nd, 3rd and 4th parts)
- Ascending colon
- Descending colon
- Pancreas
- Kidneys
- Ureters
- Aorta
- Inferior vena cava
List the intraperitoneal structures:
- Stomach
- Duodenum (1st part)
- Jejunum
- Ileum
- Transverse colon
- Sigmoid colon
What cells line the gallbladder, small intestine, stomach and large intestine?
Simple columnar
What is Crohn’s disease?
A disorder of unknown aetiology characterised by transmural (the entire wall) inflammation of the GI tract. This may involve any or all parts of the GI tract from the mouth to perianal area.
What is the most common area of the GI tract affected in Crohn’s disease?
Terminal ileal and perianal locations
What are the complications of Crohn’s disease?
- Fibrosis leading to intestinal strictures and obstruction
- Bowel perforations and fistulae
- Adhesions
- Small bowl and colorectal cancer
- Osteoporosis
What are the three endoscopic findings specific to the diagnosis of Crohn’s disease?
1) Aphthous ulcers
2) Cobblestoning (normal tissue between ulcers)
3) Skip/discontinuous lesions
What are the clinical signs and symptoms of Crohn’s disease?
- Weight loss
- Lethargy
- Diarrhoea (non-bloody)
- Abdominal pain
- Perianal skin tags or ulers
What blood results would you see in someone presenting with Crohn’s disease for the first time?
- Anaemia
- Iron deficiency
- Low serum B12
- Low serum folate
- Hypo- albuminemia, cholesterolaemia and calcaemia
- Elevated CRP
What treatments are used to induce remission in Crohn’s disease?
- Glucocorticoids e.g. budesonide
- Enteral feeding
What treatments are used to maintain remission in Crohn’s disease?
Azathioprine or mercaptopurine
What is ulcerative colitis?
A type of inflammatory bowel disease characterised by diffuse inflammation of the colonic mucosa and a relapsing, remitting course
What are the key features of the first presentation of someone with ulcerative colitis?
- Rectal bleeding
- Diarrhoea
- Blood in stool
- Faecal urgency
- Tenesmus
- Lower-left quadrant abdominal pain
What is tenesmus?
The feeling that you need to pass stool even though your bowel is empty
Why should colonoscopy be avoided in a patient with severe ulcerative colitis? What is preferred?
Because there is a high risk of perforation. Flexible sigmoidoscopy is preferred
What are the diagnostic findings from endoscopy in a patient with ulcerative colitis?
- Red, raw mucosa that bleeds easily
- No inflammation beyond the submucosa
- Pseudopolyps
- Mucosal granularity
What histological findings do you see in a patient with ulcerative colitis?
- Crypt abscesses
- Depletion of goblet cells and mucin from gland epithelium
- Absence of granulomata
- Inflammatory cell infiltration in lamina propria
What is the treatment for acute-severe ulcerative colitis?
IV corticosteroids
What findings do you see on a barium enema from a patient with ulcerative colitis?
- Loss of haustrations
- Superficial ulceration (pseudopolyps)
- Colon narrow and short ‘drainpipe colon’ in long-standing disease
What is the treatment for mild to moderate ulcerative colitis?
Aminosalicylate e.g. mesalazine, either topical or oral depending on severity of disease
What do you give if remission is not achieved with aminosalicylates in patients with ulcerative colitis?
Oral corticosteroids
What is the first-line treatment for moderate to severe ulcerative colitis?
Oral corticosteroids with a biological agent e.g. prednisolone with infliximab
The drug for maintenance therapy of ulcerative colitis depends ________________________.
On the drug used to achieve remission
What is the difference between mild, moderate and severe ulcerative colitis?
- Mild = < 4 stools/day, no systemic disturbance
- Moderate = 4-6 stools/day, minimal systemic disturbance
- Severe = >6 stools/day with blood, systemic disturbance
What is the treatment for anal fissures when conservative management has failed?
Topical glyceryl trinitrate
What is a c. difficile infection characterised by?
Inflammation of the colon and the formation of pseudomembranes
