Gastroenterology 3 Flashcards
Villous adenoma
- Colonic polyps that have potential for malignant transformation
- Secretes large amount of mucous resulting in electrolyte disturbance
- Non speific lower GI symptoms
- Secretory diarrhoea
- Microcytic anaemia
- Hyperkalaemia
Angiodysplasia
- Vascular deformity of GI tract predisposing to bleeding and IDA
- Associated with aortic stenosis
- Diagnosis with colonoscopy, mesenteric angiography, ‘fern tree’ pattern
- Management - endoscopic cautery or argon plasma coagulation, TXA
Bile-acid malabsorption
- Chronic diarrhoea
- excessive production of bile acid or secondary to cholecytectomy, coeliac disease or SIBO
- Investigate with SeHCAT
- Managed with bile acid sequestrants - cholestyramine
Causes of raised ferritin without iron overload
Inflammation (due to ferritin being an acute phase reactant)
Alcohol excess
Liver disease
Chronic kidney disease
Malignancy
The best test to see whether iron overload is present is transferrin saturation. Typically, normal values of < 45% in females and < 50% in males exclude iron overload.
Ischaemia to lower GIT
Three categories
Common predisposing factors
How does it present
- Acute mesenteric ischaemia, chronic mesenteric ischaemia, ischaemic colitis
- Increasing age, AF, endocarditis, malignancy (embolic), cardiovascular risk factors
- Presents with abdo pain sudden onset, severe, rectal bleeding, diarrhoea, fever
Mesenteric ischaemia vs ischaemic colitis
- Mesenteric ischaemia - typically small bowel due to embolism, sudden abdo pain needing urgent surgery with high mortality
- Ischaemic colitis is usually large bowel, transient less severe symptoms, bloody diarrhoea with thumbprinting, conservative management
Action of maltase, sucrase and lactase
maltase: cleaves disaccharide maltose to glucose + glucose
sucrase: cleaves sucrose to fructose and glucose
lactase: cleaves disaccharide lactose to glucose + galactose
Microscopic colitis
Chronic inflammatory condition of gut, name 4 main risk factors
- Smoking
- NSAIDS
- PPIs
- SSRIs
Microscopic colitis presentation and associations
Presentation
* Diarrhoea, weeks to months, 4-10 bowel movements
* Abdo pain
* Fecal urgency and incontinence
* Bloating, flatulence
* Weight loss
* Nocturnal diarrhoea
Associated with
* Joint pain
* Erythema nodosum, pyoderma gangrenosum
* Autoimmune disease
Small bowel bacterial overgrowth syndrome
- Excessive amounts of bacteria in the small bowel resulting in gastrointestinal symptoms
- Risk factors: neonates, scleroderma, DM
- Presents like IBS
- Diagnosed by hydrogen breath test or trial of antibiotics (Rifaximin)
Hepatocellular carcinoma
Risk factors
- Liver cirrhosis from Hepatitis B, C, Alcohol, haemachromatosis, PBC
- alpha-1 antitrypsin deficiency
- Aflatoxin
- COCP, anabolic steroids
- Poryphyria
- DM
- Late presentation with features of liver cirrhosis, decompensated CLD, raised AFP
HCC
Diagnosis
Screening with ultrasound (+/- alpha-fetoprotein) should be considered for high risk groups such as:
patients liver cirrhosis secondary to hepatitis B & C or haemochromatosis
men with liver cirrhosis secondary to alcohol
Management options
early disease: surgical resection
liver transplantation
radiofrequency ablation
transarterial chemoembolisation
sorafenib: a multikinase inhibitor
Difference between Gilbert’s syndrome and Dubin Johnson syndrome
Dubin-Johnson syndrome is a benign autosomal recessive disorder resulting in hyperbilirubinaemia (conjugated, therefore present in urine).
Gilbert’s syndrome - caused by unconjugated bilirubin high levels
Dubin Johnson syndrome
It is due to a defect in the canillicular multispecific organic anion transporter (cMOAT) protein. This causes defective hepatic bilirubin excretion.
