gastro

• A faecal calprotectin would be an appropriate first line investigation for inflammatory bowel disease.
• A schilling test involves administering radiolabeled B12. Given that artificial B12 replacement is now widely available it is generally no longer needed.
• TTG is a first line blood test to investigate coeliac disease, it would be particularly important if there was an iron-deficiency anaemia.
• Per NICE guidelines, a non-urgent referral for an upper gastrointestinal endoscopy should be considered for a 65-year-old man presenting with symptoms of upper abdominal pain, nausea, occasional vomiting, and thrombocytosis (elevated platelet count). It is essential to rule out oesophageal and gastric malignancies; therefore, endoscopic evaluation is warranted. While there is no dysphagia or weight loss, then non-urgent referral is recommended.
• Selective serotonin reuptake inhibitors such as citalopram, corticosteroids such as prednisolone, and non-steroidal anti-inflammatory drugs such as aspirin, can all contribute to heartburn symptoms. According to NICE guidelines, a trial of full-dose PPI should be tried for patients with undiagnosed dyspepsia regardless of whether they're on medications that predispose them to reflux or ulceration.
• Infliximab therapy is typically reserved for patients with moderate to severe ulcerative colitis, particularly those who have not responded to both aminosalicylates and corticosteroids.
• The severity of UC is usually classified as being mild, moderate or severe:

  • mild: < 4 stools/day, only a small amount of blood
  • moderate: 4-6 stools/day, varying amounts of blood, no systemic upset
  • severe: >6 bloody stools per day + features of systemic upset (pyrexia, tachycardia, anaemia, raised inflammatory markers)
• Methotrexate is not recommended for the management of UC (in contrast to Crohn's disease)
• Cholestyramine works by binding to bile acids in the small intestine and promoting their reabsorption into the cycle of bile acid production, which will address the cause of diarrhoea following a cholecystectomy which causes more water and salts to be lost in the stool and a faster transit time of stool through the intestines.
• Bismuth can be used for diarrhoea more generally, such as to prevent symptoms during infective diarrhoea, however will not fix the long-term problem.
• Creon is used to replace pancreatic enzymes, for example in cystic fibrosis where there is a reduction in pancreatic enzymes reaching the intestine.
• Rehydration salts help to replace depleted electrolytes, usually in acute diarrhoea.
• Bile-acid malabsorption is a cause of chronic diarrhoea. This may be primary, due to excessive production of bile acid, or secondary to an underlying gastrointestinal disorder causing reduced bile acid absorption. It can lead to steatorrhoea and vitamin A, D, E, Kmalabsorption.
• Oesophageal varices - Usually a large volume of fresh blood. Swallowed blood may cause melena. Often associated with haemodynamic compromise. May stop spontaneously but re-bleeds are common until appropriately managed.
• Oesophagitis - Small volume of fresh blood, often streaking vomit. Malena rare. Often ceases spontaneously. Usually history of antecedent GORD type symptoms.
• Mallory Weiss tear - Typically brisk small to moderate volume of bright red blood following a bout of repeated vomiting. Malena rare. Usually ceases spontaneously.
• Gastric ulcer - Small low volume bleeds are more common so would tend to present as iron deficiency anaemia. Erosion into a significant vessel may produce considerable haemorrhage and haematemesis.
• Duodenal ulcer - These are usually posteriorly sited and may erode the gastroduodenal artery. However, ulcers at any site in the duodenum may present with haematemesis, melena and epigastric discomfort. The pain of a duodenal ulcer is slightly different to that of gastric ulcers and often occurs several hours after eating. Periampullary tumours may bleed but these are rare.
• co-amoxiclav and clarithromycin, as a treatment for pneumonia, are highly associated with C. difficile infection
• Neurological symptoms (behavioural and speech problems, clumsiness), excessive salivation, along with a family history of liver disease, is suggestive of Wilson's disease. Wilson's disease is an autosomal recessive disorder characterised by defective copper transport, leading to copper accumulation, particularly in the liver and brain. Penicillamine is a copper chelating agent that promotes urinary excretion of copper and is considered first-line treatment for symptomatic patients with Wilson's disease in the UK.
• Wilson's disease is an autosomal recessive disorder characterised by excessive copper deposition in the tissues. Metabolic abnormalities include increased copper absorption from the small intestine and decreased hepatic copper excretion. Wilson's disease is caused by a defect in the ATP7B gene located on chromosome 13.The onset of symptoms is usually between 10 - 25 years. Children usually present with liver disease whereas the first sign of disease in young adults is often neurological disease
• Ferritin and transferrin saturation are the most useful investigations for monitoring the adequacy of venesection. Transferrin saturation should be kept below 50% and the serum ferritin concentration below 50 ug/L. Please note that these figures are different from the haemochromatosis diagnostic values (transferrin saturation >55% in men and >50% in women, ferritin >500 ug/L).
• Ischaemic hepatitis is often characterised by marked elevation in aminotransferase liver enzymes (AST and ALT) which peak 1-3 days after the insult. There is often a significant rise in lactate dehydrogenase (LDH) which is sensitive for ischaemic hepatitis compared to other causes of liver injury.
• SAAG

  Indirectly measures portal pressure and can be used to determine if a patient's ascites is due to portal hypertension or other causes
• High SAAG (>11g/L)

  • Indicates portal hypertension and the ascitic fluid is a transudate
  • Causes include liver cirrhosis, hepatic failure, venous occlusion (e.g. Budd Chiari syndrome), alcoholic hepatitis, and kwashiorkor malnutrition
• Low SAAG (<11g/L)

  • Suggests the ascitic fluid is an exudate
  • Causes include malignancy, infection, pancreatitis and nephrotic syndrome
• Bowel malignancy, nephrotic syndrome and pancreatitis are incorrect causes of low SAAG
• Spontaneous bacterial peritonitis is not a cause of ascites. Rather, it is a result of having ascites and liver cirrhosis. The most common bacteria are gram-negative Escherichia coli and Klebsiella pneumoniae.
• Transient elastography, also known as Fibroscan, is a non-invasive test that measures liver stiffness, which correlates with the degree of fibrosis or scarring within the liver. 
• Terlipressin is a vasoactive agent that should be administered before endoscopy, as is of benefit in initial haemostasis and preventing rebleeding. Prophylactic antibiotics have been shown to reduce mortality in patients with liver cirrhosis.
• Intravenous propranolol is administered following endoscopic variceal band ligation as it has been shown to reduce rebleeding and mortality
• Propranolol is administered following endoscopic variceal band ligation as it has been shown to reduce rebleeding and mortality compared to a placebo. Proton pump inhibitors are usually administered following the procedure to prevent endoscopic variceal band ligation-induced ulceration. There is no evidence to support the administration of both before the procedure. 
• Intrinsic factor antibodies are far more specific for the investigation of vitamin B12 deficiency.
• Hypersegmented polymorphs are an early sign of megaloblastic anaemia.
• Anti-Ro antibodies are associated with systemic lupus erythematosus (SLE), Sjogren's and other rheumatological conditions.
• Anti-TSH antibodies are associated with Graves' disease whilst thyroid peroxidase (TPO) antibodies are associated with both Graves' and Hashimoto's disease. Thyroid disease would likely result in macrocytic anaemia.
• Other drugs which may also cause cholestasis include antibiotics such as co-amoxiclav, phenothiazines, sulphonylureas, fibrates and anabolic steroids. 
• Budd-Chiari syndrome

  Hepatic vein thrombosis
• Budd-Chiari syndrome


  • Usually seen in the context of underlying haematological disease or another procoagulant condition
• Causes of Budd-Chiari syndrome

  • polycythaemia rubra vera
  • thrombophilia: activated protein C resistance, antithrombin III deficiency, protein C & S deficiencies
  • pregnancy
  • combined oral contraceptive pill: accounts for around 20% of cases