Gastroenterology Flashcards
What part of the GI tract is most commonly affected in Crohn’s?
Terminal Ileum + Colon
1st Line treatment for inducing remission in corhns?
2nd line?
add-on medication to 2nd line?
Tx for refractory cases?
Tx for isolated peri-anal disease?
1) Glucocorticoids
2) 5 ASA drugs (e.g. Mesalazine)
3) Azathioprine
refractory = Infliximab
Isolated peri-anal disease = metronidazole
Tx options for maintaining remission in Crohns?
1st line = Azathioprine/Mercaptopurine (Always check TPMT activity)
2nd line = methotrexate
Triad in Budd-Chiari syndrome?
Abdominal pain, hepatomegaly, ascites
Pathophysiology of Budd-Chiari syndrome?
Occlusion of the hepatic veins that drain the liver causes painful distension of the liver capsule and backflow portal hypertension resulting in ascites
1st line Ix for H Pylori?
13C-urea breath test
1st line Ix for small intestinal bacterial overgrowth/ carbohydrate malabsorption conditions such as lactose intolerance.
Hydrogen breath test
What is the triad for Heyde’s syndrome?
Aortic stenosis, GI Bleeding, Acquired Von Willebrand disease (type 2A)
Pathophysiology of carcinoid syndrome?
systemic release of vasoactive substances (mainly serotonin) from neuroendocrine tumors (NETs), typically arising from the gastrointestinal tract, bronchial tree,
5 clinical features of carcinoid syndrome?
1) Flushing
2) Diarrhoea
3) Bronchospasm
4) Right sided valvular heart disease
5) Pellagra symptoms
(Niacin deficiency (due to diversion of tryptophan for serotonin synthesis))
1st line investigation for suspected carcinoid syndrome?
Urinary 5-HIAA
(Serotonin is broken down into 5-hydroxyindoleacetic acid (5-HIAA))
MOA Terlipressin?
Results in vasoconstriction of the vasopressin V1 receptors located on vascular smooth muscle. Vasoconstriciton of splanic arteries reduced blood flow to the portal venous system
How does a transjugular intrahepetic portosystemic shunt (TIPS) procedure work in Variceal Haemorrhage?
Connects hepatic vein to portal vein reducing portal pressure
SE: exacerbates hepatic encephalopathy
Pathophysiology of wilsons disease?
Defective copper transport in hepatocytes
Reduced incorporation into ceruloplasmin
copper builds up in liver and spells into blood stream
Hepatic manifestations of wilsons disease?
Acute liver failure ( Coombs-negative hemolytic anemia)
Neurological manifestations of wilsons disease?
Parkinsonism symptoms (Primarily deposited in basal ganglia -> Putamen and Globus Pallidus
Ophthalmological signs of Wilsons Disease?
Kayser-Fleischer rings
Inheritance pattern of Wilsons disease?
Autosomal recessive (Mutations in the ATP7B gene)
1st line management of Wilsons disease (chelation)
D-penicillamine
Trientine
Aetiology of Zollinger-Ellison syndrome?
Gastrinomas are found in in the gastrinoma triangle:
Duodenum, Pancreas, Peripancreatic lymph nodes
Triad of Zollinger-Ellison syndrome?
Peptic ulcer disease, diarrhoea, reflux symptoms
Number 1 Ix for Zollinger-Ellison syndrome?
Serum Gastrin levels (have to be of PPI)
Medical Mx of Zollinger-Ellison syndrome?
1) High dose PPI
2) Somatostain Analogs (e.g. Octreotide)
Most common organism indicated in Ascites?
E. Coli
Cause of whipple disease?
Gram positive bacillus Tropheryma whipplei
Gold standard for diagnosing Whipple disease and finding?
Small Bowel Biopsy (Gold Standard):
Periodic acid–Schiff (PAS)-positive macrophages in the lamina propria
Triad for whiples disease?
Chronic diarrhoea, weight loss, arthralgia
Threadworms
-Most common cause?
-Symptoms?
-Tx?
-Enterobius vermicularis
-Perianal itching/Vulval symptoms
-mebendazole
Spot diagnosis:
Elevated ALP in a middle aged wormen, with fatigue and pruritis, AMA positive?
Primary Biliary Cholangitis
Pathophysiology of PBC?
Autoimmune destruction of small intrahepatic bile ducts by antimitochondrial antibodies (AMAs) and T lymphocytes.
Leads to cholestasis, bile acid accumulation, and progressive liver damage.
Tx for PBC?
Ursodeoxycholic acid (UDCA)
Young female with fatigue, arthralgia, and jaundice. Raised ALT/AST. Positive immunoglbulin igM
Autoimmune hepatitis
What autoantibodies are associated with:
-Type 1 AIH?
-Type 2 AIH?
ANA+SMA
Anti-LKM1
1st line management for autoimmune hepatitis?
Prednisolone + Azathioprine
Role of gastrin hormone in the stomach?
Stimulates secretion of gastric acid by parietal cells
Promotes gastric motility
Gastrin stimuli of release?
Distention of stomach, presences of peptide, vagal stimulation
Site of release of Gastrin?
G-cells in antrum of stomach
Mnemonic for gastrin role and function?
Gastrin for “Gas” in the stomach – It revs up acid production for digestion.
Cholecystokinin (CCK)
Two key roles?
1) Gallbladder contraction to release bile
2) Stimulates pancreatic enzyme secretion
Stimuli for release of CCK?
Fatty acids, monoglycerides, and amino acids in the duodenum
Site of release CCK?
I cells (duodenum)
Action of CCK?
CCK binds to receptors on the gallbladder and pancreas, promoting bile and enzyme release. It also reduces gastric motility
Mnemonic for remembering function of CCK?
“Chewing up fats” – Think bile and pancreatic enzymes breaking down fat
3 main functions of secretin?
1) Bicarbonate secretion from pancreas
2) Inhibits gastric acid secretion
3) Enhances bile flow
Stimulus for release of secretin?
Acidic chyme (low pH) entering the duodenum
Site of release of secretin?
S cells (duodenum)
Mnemonic for remembering role and function of secretin?
Secretin “secretly neutralizes acid” – Think of it as the pH balancer
Vasoactive Intestinal Peptide (VIP) role? (3)
1) Stimulates intestinal secretion of water and electrolytes
2) Relaxes smooth muscle in the GI tract
3) Inhibits gastric acid secretion
Site of release of VIP?
Neurons in the enteric nervous system
Mnemonic for function VIP?
VIP for “Very Important Pooping” – Focuses on water secretion and smooth muscle relaxation.
Somatostatin role? (2)
Inhibits secretion of multiple hormones (gastrin, CCK, secretin, VIP, insulin, glucagon).
Reduces gastric acid and pancreatic secretion.
Stimulus for release of somatostatin?
Increased acid levels (lower pH)
Somatatostatin site of release?
D cells in stomach and pancreas
Mnemonic for somatostatin?
Somatostatin “stops” everything – It’s the master inhibitor
Where are Somatostatin analogs (e.g., octreotide) used? (two conditions)
Carcinoid syndrome
VIPomas
pigment laden macrophages or pseudomelanosis coli is indicative of what?
Laxtative abuse
Test for exocrine function of pancreas? (commonly used in chronic pancreatitis?
Faecal Elastase
Causes of pancreatitis (GET SMASHED)
Gall Stones
Ethanol
Trauma
Steroids
Mumps
Autoimmune
Scorpion Venum
Hypertriglyceridaemia, Hyperchylomicronaemia, Hypercalcaemia, Hypothermia
ERCP
Drugs (Azathioprine, Mesalazine, furosemide, steroids, valporate)
Most common autoantibody associated with Ulcerative Colitis?
p-ANCA
Agent for reducing remission in mild/moderate UC proctitis?
topical (rectal) aminosalicylate
Agent for reducing remission in mild/moderate UC proctosigmoiditis and left-sided ulcerative colitis?
topical (rectal) aminosalicylate
Agent for reducing remission in mild/moderate UC extensive disease?
topical (rectal) aminosalicylate and a high-dose oral aminosalicylate:
How to maintain remission in UC?
5-ASA (oral or rectal).
Azathioprine or mercaptopurine if frequent relapses or steroid dependence.
what other hepatobiliary condition is UC closely associated with?
Primary sclerosing cholangitis
1st line Tx for small intestinal bacterial overgrowth?
Rifaximin
1st Line management for Gastric MALT Lymphoma?
H. Pylori Eradication
T/F patients with ascites and protein concentration < 15/g should be given oral ciprofloxacilin or norfloxacilin as prophylaxis?
True
What is the Ix of choice for bile acid malabsorption?
SeHCAT (Selenium-75-labelled homocholic acid taurine)
Alternative name for Lynch Syndrome?
Hereditary non-polyposis colorectal carcinoma
Inheritance pattern of Lynch syndrome?
Autosomal dominant
Pathophysiology of Lynch Syndrome?
Mutations in genes associated with DNA Mismatch repair
Most common gene mutations associated with Lynch Syndrome?
MSH2 (60% of cases)
MLH1 (30%)
Pathophysiology of Familial Adenomatous Polyposis?
Germline mutation in the APC gene on chromosome 5
Tx options for FAP?
total proctocolectomy with ileal pouch anal anastomosis (IPAA) formation in their twenties
Variant of FAP which result in osteomas of the skull and mandible, retinal pigmentation, thyroid carcinoma and epidermoid cysts on the skin
Gardners Syndrome
When interpreting coeliac serology, what immunoglobulin level also needs to be checked?
IgA
Wilsons disease: Summary
-Inheritance pattern?
-Absence in what gene ? means that Caeruloplasmin can not be synthesised properly
-Autosomal recessive
-ATP7B