Oesophagitis

Usually viral (HSV, CMV) or fungal (candida). Can be chemical Commonest form caused by reflux of gastric acid/bile Reflux oesophagitis …

Barrett's oesophagus

Long standing reflux leads to metaplasia of stratified squamous mucosa to simple columnar mucosa/intestinal morphology Pre malignant condition …

Oesophageal carcinoma

Squamous cell carcinoma - other carcinogens - HPV, alcohol, burns... Adenocarcinoma - caused by Barrett's oesophagus - mainly caucasians …

Gastritis

Can be due to either increased aggression/attack on stomach or impaired defences. Acute - usually due to NSAIDs, alcohol or initial H. pylori infe…

Peptic ulcer disease

Localised defect extending at least into submucosa First part of duodenum, junction of antral/body mucosa, distal oesophagus most common sites …

Gastric Cancer

Most commonly adenocarcinoma, less freq endocrine tumours, lymphomas, stromal tumours. TNM staging Adenocarcinoma of GOJ associated with reflux, b…

Coeliac Disease

Immune mediated enteropathy when ingestion of wheat, rye or barley - anything containing gliadin Increased CD8+ intraepithelial lymphocytes V…

Liver Tumours

Benign Liver tumours Hepatocyte adenoma - may be multiple, often driven by exogenous steroids, can be fatal if rupture Bile duct adenoma - lots…

Ulcerative Colitis vs Crohn's disease

Ulcerative Colitis Crohn's Disease Distribution Rectum/colon Any part of GIT Histology…

Ischaemic bowel disease

Transient - 80% Acute fulminant & gangrenous Chronic segmental ulcerating (ischaemic stricture) Occlusive - arterial embolism Non-occ…

Diverticular disease

High intra-lumen pressure (due to lack of fibre) cause protrusions of mucosa and submucosa through the bowel wall - commonly sigmoid colon (areas tha…

Colorectal polyps

Kinda opposite to diverticulitis - mucosal protrusion into lumen. Solitary or multiple, pedunculated, sessile or flat, small or large, due to patholo…

Colorectal cancer

3rd most common cancer (behind lung, breast/prostate) - TNM (was previously Dukes') Most common moderately well differentiated adenocarcinoma …

Haemochromatosis

Inborn error of iron metabolism causing accumulation in: Liver $\to$ cirrhosis Pancreas $\to$ diabetes Skin \…

Wilson's disease

Inborn error of copper metabolism that usually presents at a younger age. Copper accumulates in: Liver $\to$ cirrhosis Eyes \(…

Alpha 1 antitrypsin deficiency

Inherited abnormal anti-protease which cannot be exported from hepatocyte Accumulates in liver cells and damages them - cirrhosis Insufficien…

Liver function tests

ALT - Liver Tissue ALP - Liver Pipes  Test Description Alanine transaminase (ALT) An enzyme that is …

Pancreatitis

Acute - gland reverts to normal if underlying cause removed Chronic - irreversible loss of tissue Acute Relatively common - damage to exocri…

Pancreatic ductal adenocarcinoma

Most common pancreatic cancer - usually in head of pancreas ↑ risk with chronic pancreatitis, DM, alcohol Hereditary with Lynch synd…

Pancreatic cancer

Ductal adenocarcinoma Most common pancreatic cancer - usually in head of pancreas ↑ risk with chronic pancreatitis, DM, alcohol H…

Bowel Obstruction

Vomiting Constipation Colic Distension Causes Common Rare Hernias (small bowel) Strictures (Cr…

Necrotising enterocolitis

Necrotising enterocolitis (NEC) is a life-threatening illness almost exclusively affecting neonates. Inflammation of the intestine leading …

Ascites

Sodium and water retention - peripheral arterial vasodilation which causes a reduction in BV. This reduction activates the RAAS promoting ret…

Perianal abscess

Infective-inflammatory collection within the perianal region - often associated with perianal fistulae  Infection and anal gland drainage obs…

Stomach and oesophagus physiology

Oesophagus Nerve plexus on it so need to be careful  Through diaphragm T10    Stomach Secretions: …

Upper GI secretions

Secretions: What Source Bile salts Liver Bicarbonate ions Pancreas Trypsin, chym…

Colon physiology

Bacterial digestion Fibre $\to H_2+C{H}_4+\text{short chain fatty acids}$ Urea + amino acids $\to N{H}_4$ Bili…

Peritoneal reflections

Parietal peritoneum - layers lining the surface walls  Visceral peritoneum - layer that covers a larger continuous layer like pleura  …

Small intestine anatomy

Duodenum 4 parts:  Wraps around head of pancreas Supplied by celiac trunk, SMA, sup, mid & inferior pancreaticoduodenal artery …

Rectum physiology

Rectal valves reduce pressure on sphincters from gravity Sharp angles slows stools  …

Celiac trunk

GI Embryology

Gut tube Dorsal mesentery (back) from lower oesophagus to cloaca Ventral mesentery (front) from lower oesophagus to 1st part of duodenum Tra…

Clostridium Difficile

Gram-positive, rod-shaped anaerobe Opportunistic when antibiotics remove other bacterial competition and can get out of control. Toxins produed - …

Haemorrhoids

Abnormal swellings of the vascular mucosal anal cushions around the anus. Women are predisposed to developing haemorrhoids during pregnancy - bulk…

Anal fissure

A tear in the mucosal lining of the anal canal - most commonly due to trauma from defecation Acute - present for less than 6 weeks Chronic - pr…

Wernicke-Korsakoff syndrome

Alcohol prevents the absorption of thiamine by blocking thiamine pyrophosphate synthetase, resulting in thiamine deficiency. The main sy…

Gastrointestinal perforation

Four mechanisms that lead to perforation: Ischemia (bowel obstruction, necrosis) Infection (appendicitis, diverticulitis) Erosion (malignan…

Malnutrition

Nutrition via gastrointestinal tract - enteral feeding Mouth NG Percutaneous endoscopic gastrostomy (PEG) - tube from the surface of abdo t…

Sulphasalazine

Aminosalicylate - to reduce inflammation. Used in the treatment of ulcerative colitis and rheumatoid arthritis Can cause haemolytic anaemia wi…

Pharyngeal pouch

dysphagia regurgitation halitosis age 70+ surgical resection

Spontaneous Bacterial Peritonitis

A form of peritonitis, usually seen in patients with ascites secondary to liver cirrhosis Abdominal pain and fever in patients with ascites D…

Gaviscon

Drug Class Antacids Mechanism Weak alkali to neutralise stomach acid Alginate component ↑ s…

Ranitidine

Drug Class H2 Antagonist Mechanism Competitively inhibits histamine actions at all H2 receptors, mainly inhibiting ga…

Omeprazole

Drug Class Proton pump inhibitor Mechanism Inhibits gastric acid secretion by dose-dependent inhibition of proton pum…

Loperamide

Drug Class Anti-diarrhoeal agent Mechanism Acts on opioid receptors in myenteric plexus to inhibit peristalsis (inhib…

Senna

Drug Class Stimulant laxative Mechanism Hydrolysed in colon to stimulate myenteric plexus, smooth muscle activity …

Mesalazine

Drug Class Aminosalicylates Mechanism Release 5-aminosalicyclate acid in the bowel Typical Dose 2.4-4…

Metoclopramide

Drug Class Antiemetic (dopamine antagonist) Mechanism Blocks dopamine receptors in chemoreceptor trigger z…

H. pylori eradication

Gram -ve aerobic bacteria Diagnosis: Rapid urease test during endoscopy Stool antigen test for screening Urea breath test to check treat…

PR Bleeding

Most common: Diverticulosis Haemorrhoids Ischaemic or infective colitis Malignancy

Diahorrea causes

Campylobacter jejuni typically causes bloody stools and abdominal pain.  Clostridium difficile infection typically follows a hosp…