By CRUX OF SURGERY in MRCS Part A — 23 Feb 2026

Biliary System

👩‍⚕️ It's easiest to learn by working through the MCQs. Get to grips with the anatomy, physiology, and management of the different pathologies.

A 30-year-old woman has RUQ pain after eating fatty meals. Bilirubin is normal. Diagnosis?

((Biliary colic::☑️ Intermittent post-prandial RUQ pain with normal bilirubin suggests transient cystic duct obstruction))
((Cholangitis::Would present with fever and jaundice))
((Cholecystitis::Would present with persistent pain, fever, and inflammatory markers))
((Pancreatitis::Typically epigastric pain radiating to the back with raised amylase))

A female has ultrasound-confirmed gallstones and normal ducts. She is suffering with biliary colic. Management?

((Elective laparoscopic cholecystectomy::☑️ Symptomatic gallstones with normal ducts; definitive treatment is laparoscopic removal))
((ERCP::Indicated if common bile duct stones suspected; ducts are normal))
((Conservative management::Not appropriate for ongoing symptomatic biliary colic))
((MRCP::Used to assess ductal stones; not required with normal ducts on USS))

A woman with a two-year history of intermittent right upper abdomen pain now has right upper abdomen pain and a fever. LFT and FBC are normal. Next step?

((Ultrasound abdomen::☑️ First-line investigation for suspected gallstone disease or acute cholecystitis))
((CT abdomen::Not first-line for uncomplicated suspected biliary pathology))
((ERCP::Reserved for suspected choledocholithiasis or cholangitis))
((MRCP::Used to assess bile ducts if obstruction suspected, not initial test))

A 35-year-old woman presents with recurrent episodes of RUQ colicky pain. Ultrasound shows multiple small gallstones with increased wall thickness and a normal common bile duct. Next step?

((Elective cholecystectomy::☑️ Recurrent symptomatic gallstones; normal CBD so proceed to laparoscopic cholecystectomy))
((ERCP::Indicated only if CBD stones or obstruction suspected))
((Conservative management::Recurrent biliary colic warrants definitive surgery))
((MRCP::Used to evaluate CBD stones; CBD already normal on USS))

A 32-year-old man presents with fever, upper quadrant pain, pale stool, and dark urine. Diagnosis?

((Acute cholecystitis::Causes RUQ pain and fever but does not produce pale stools or dark urine))
((Chronic cholecystitis::Typically recurrent pain without obstructive jaundice features))
((Carcinoma head of pancreas::Usually painless progressive jaundice rather than acute febrile illness))
((Gilbert syndrome::Causes mild unconjugated hyperbilirubinaemia without pale stools or fever))
((Cholangitis::☑️ Fever, RUQ pain, and obstructive jaundice features (dark urine, pale stool) suggest ascending cholangitis))

A patient has cholangitis, sepsis, and obstructive jaundice. Definitive management?

Endoscopic retrograde cholangiopancreatography (ERCP) ± sphincterotomy and stenting

💡 Treatment of ascending cholangitis: Initial resuscitation with IVF and IV broad-spectrum antibiotics, then biliary drainage for which ERCP is 1^L but if ERCP is not possible because they’re too sick, then percutaneous transhepatic cholangiography PTC can be used. In the long term the cause for the cholangitis should be identified and managed as appropriate. Patients may require a cholecystectomy if gallstones were the underlying cause. In cases of unresectable cancers, palliative care may involve placing self-expandable metal stents SEMS to maintain biliary tract patency.

An elderly man presents with RUQ pain, nausea, and vomiting. Abdominal imaging shows pneumobilia. Diagnosis?

((Gallstone ileus::☑️ Pneumobilia indicates a cholecysto-enteric fistula allowing air into the biliary tree; Gallstone ileus triad: SBO + pneumobilia + ectopic gallstone))
((Acute cholecystitis::Does not cause pneumobilia))
((Ascending cholangitis::May cause sepsis but not bowel obstruction from migrated stone))
((Small bowel obstruction (adhesions)::Would not explain pneumobilia))

💡 In gallstone ileus: A cholecysto-enteric fistula forms → Air enters the biliary tree (pneumobilia) → A stone migrates → Obstruction occurs. The management of gallstone ileus involves stabilisation with urgent fluid resuscitation and nasogastric decompression followed by simple enterolithotomy or combined single-stage stone removal with cholecystectomy and fistula repair.

A man had a cholecystectomy a few weeks ago. He now presents with intermittent jaundice. Diagnosis?

((Carcinoma pancreatic head::Typically causes progressive painless jaundice, not intermittent episodes soon after surgery))
((Mirizzi syndrome::Caused by impacted stone in cystic duct compressing CBD; unlikely after gallbladder removal))
((Residual stone in bile duct::☑️ Retained CBD stone after cholecystectomy can cause intermittent obstructive jaundice))
((Cholangitis::Would present with fever and systemic sepsis in addition to jaundice))

💡 Retained choledocholithiasis is a common cause of post-cholecystectomy intermittent obstructive jaundice weeks after surgery, as the stone causes episodic obstruction as it moves.

A 42‑year‑old woman develops a self‑limiting postoperative wound infection after cholecystectomy. By what process is bacterial ingestion by phagocytes enhanced?

((Apoptosis::Programmed cell death; does not enhance bacterial ingestion))
((Autophagy::Intracellular degradation pathway, not primary mechanism for enhancing phagocytosis))
((Metaplasia::Cellular adaptation; unrelated to immune ingestion))
((Opsonization::☑️ Coating of bacteria with antibody or complement (e.g. C3b) enhances phagocytosis))
((Phagocytosis::The act of ingestion itself; enhancement occurs via opsonization))

A 45-year-old woman undergoes cholecystectomy for multiple gallstones. Which effect is most likely post-cholecystectomy?

((Decrease bile reflux into stomach::Bile may actually reflux more due to continuous flow into duodenum))
((Decrease cholesterol metabolism::Cholesterol metabolism is not significantly reduced))
((Decrease common bile duct capacity::CBD often dilates to compensate after gallbladder removal))
((Decrease enterohepatic circulation of bile salts::Enterohepatic circulation is not reduced post-cholecystectomy))
((Decrease maximum bile flow after large meals::☑️ There is no longer a bile reservoir so the ability to deliver large bolus of bile after fatty meals is reduced and so post-meal peak flow is reduced and flow becomes continuous))

💡 Changes expected to occur post-cholecystectomy

Loss of reservoir function → Bile flows continuously into the duodenum, and no large boluses are released after fatty meals → Reduced post-prandial peak bile delivery

CBD often dilates to compensate after gallbladder removal
Hepatic bile production remains unchanged
Bile salt synthesis remains unchanged
Enterohepatic circulation continues normally - it's not reduced

Which of the following changes is expected after cholecystectomy?

((Decreased secretion of bile salts::Hepatic bile salt secretion remains unchanged))
((Reduced enterohepatic circulation of bile salts::Enterohepatic recycling continues normally))
((Increased production of bile acids::Bile acid synthesis is not significantly increased))
((Elevated bile salt secretion::Removal of the gallbladder does not increase hepatic secretion))
((None of the above::☑️ Cholecystectomy alters bile storage and delivery, not production or circulation))

ERCP is performed for a benign CBD stricture. Twelve hours later the patient develops fever and abdominal pain. Diagnosis?

((Gallstone::Does not explain acute post-ERCP fever))
((Cholangitis::☑️ Post-ERCP ascending infection; fever and RUQ pain suggest Charcot’s triad))
((Biliary duct injury::Would cause bile leak and peritonitis rather than infective picture))
((Duodenal rupture::Would present with severe peritonitis and systemic instability))

💡 Post-ERCP cholangitis is caused by bacterial contamination during the procedure. It is more likely if there was incomplete drainage of the biliary system. Symptoms include Charcot's triad of fever, right upper quadrant or epigastric pain and jaundice. Reynolds' pentad includes these plus confusion/mental status changes and hypotension/shock. E. coli is the most common organism causing cholangitis infections.

A 33-year-old lady presented with jaundice secondary to common bile duct stones. A cholecystectomy and common bile duct exploration is performed and the bile duct is closed over a T tube. Six weeks postoperatively a T-tube cholangiogram is performed and shows no residual stones. The T-tube is removed and five hours after removal, a small amount of bile is noted to be draining from the T-tube site. What is the best course of action?

((Await spontaneous resolution::☑️ Small bile leak after T-tube removal is common and usually seals spontaneously))
((Arrange MRCP::Not indicated if prior cholangiogram confirmed no obstruction))
((Arrange ERCP::Reserved for persistent or large bile leak))
((Return to theatre for CBD exploration::No evidence of retained stones or major leak))
((Reinsert T-tube::Not required for minor transient leak))

💡 A T-tube is typically removed after 2 to 6 weeks once healing is complete and a cholangiogram shows no obstruction or stones. After removal, a small amount of bile drainage is normal through the tract and usually seals spontaneously.

During a cholecystectomy the surgeon identifies the hepatocystic triangle. What forms its medial border?

((Cystic artery::Traverses the triangle; is ligated during cholecystectomy))
((Common hepatic duct::☑️ Common hepatic duct forms the medial border of the hepatocystic triangle))
((Common bile duct::Not a border))
((Cystic duct::Cystic duct forms the inferior border))
((Portal vein::Posterior structure, not a boundary of the triangle))

💡 Borders of Calot’s Triangle

Medial: Common hepatic duct
Inferior: Cystic duct
Superior: Inferior surface of the liver

The common bile duct lies further laterally and inferiorly, and the hepatic artery lies posterior to the triangle.

Which structure is a content of Calot’s triangle and ligated during cholecystectomy?

((Cystic artery::☑️ Content of Calot’s triangle and routinely ligated during cholecystectomy))
((Aberrant left hepatic artery::Not a typical content of Calot’s triangle))
((Cystic duct::Forms a boundary of the triangle))
((Hepatic duct::Forms the medial border))
((Common hepatic duct::Forms the medial border and is not ligated))

💡 Contents of Calot’s Triangle:

Cystic artery
Lymph node of Lund
Sympathetic nerve fibres
Accessory hepatic ducts or arteries

Which structure is most at risk of injury when the free edge of the lesser omentum is clamped during surgery?

((Common bile duct::☑️ Lies in the free edge of the lesser omentum (hepatoduodenal ligament) and is anterior and to the right))
((Hepatic artery proper::Also within the hepatoduodenal ligament but medial to the bile duct))
((Portal vein::Posterior structure within the hepatoduodenal ligament))
((Inferior vena cava::Posterior to the epiploic foramen, not within the free edge))

💡 Contents of the hepatoduodenal ligament:

Common bile duct
Hepatic artery proper
Hepatic portal vein

The Pringle manoeuvre involves clamping the hepatoduodenal ligament, which forms the free edge of the lesser omentum. This reduces the flow of blood through the hepatic artery proper and hepatic portal vein, minimising bleeding during liver procedures. The common bile duct is the most anterior and lateral structure and the most at risk.

During a liver resection a surgeon performs a Pringle’s manoeuvre to control bleeding. Which structure will lie posterior to the epiploic foramen at this level?

((Hepatic artery::Lies within the hepatoduodenal ligament anterior to the foramen))
((Cystic duct::Not related to the posterior boundary of the epiploic foramen))
((Greater omentum::Hangs from greater curvature; not forming the posterior boundary))
((Superior mesenteric artery::Arises from the aorta inferiorly, not at the foramen))
((Inferior vena cava::☑️ Forms the posterior boundary of the epiploic (Winslow) foramen))

💡 The epiploic foramen (foramen of Winslow) is the natural opening that connects the greater sac to the lesser sac of the peritoneal cavity. When you perform Pringle’s manoeuvre, you put your finger through this foramen to compress the structures in the hepatoduodenal ligament. The borders of the epiploic foramen of Winslow are:

Anterior: Hepatoduodenal ligament
Posterior: Inferior vena cava
Superior: Caudate lobe of the liver
Inferior: First part of the duodenum

A girl presented with jaundice. She has a history of a splenectomy and has spherocytosis. Diagnosis?

((Gilbert syndrome::Causes mild unconjugated hyperbilirubinaemia without haemolysis))
((Liver cirrhosis::Would present with chronic liver failure features))
((Cholangitis::Causes obstructive jaundice with fever and RUQ pain))
((Haemolytic jaundice from hereditary spherocytosis::☑️ Ongoing haemolysis causes unconjugated hyperbilirubinaemia))

💡 Hereditary spherocytosis presents in young patients with anaemia, splenomegaly, jaundice, and a family history of members having splenectomies. Intercurrent illness can trigger acute symptoms. Severe cases need splenectomy.

Which types of stones are seen in patients with hereditary spherocytosis?

((Black pigment stones::☑️ Chronic haemolysis increases unconjugated bilirubin leading to calcium bilirubinate stone formation))
((Cholesterol stones::Associated with obesity and metabolic risk factors))
((Brown pigment stones::Usually related to infection and biliary stasis))
((Calcium oxalate stones::Seen in renal stones, not gallbladder))
((Mixed stones::Not the classic association with haemolysis))

Which are pigment gallbladder stones mainly composed of?

((Calcium oxalate::Component of renal stones, not gallstones))
((Calcium bilirubinate::☑️ Pigment stones are primarily composed of calcium salts of unconjugated bilirubin))
((Cholesterol::Main component of cholesterol stones, not pigment stones))
((Bile salts::Contribute to bile composition but not primary stone component))
((None of the above::Correct composition is listed above))

A patient with haemolysis develops gallstones. What type of gallstones are they likely to be?

((Bile salt::Not a primary component of gallstones))
((Cholesterol::Seen in metabolic syndrome; not classically linked to haemolysis))
((Calcium bilirubinate::☑️ Haemolysis increases unconjugated bilirubin, leading to pigment stone formation))
((Calcium oxalate::Component of renal stones, not gallstones))
((Triglycerides::Not a constituent of gallstones))

💡 Unconjugated hyperbilirubinaemia occurs when the production of bilirubin exceeds the liver’s ability to conjugate it, or when hepatic conjugation is impaired. Common causes include chronic haemolysis (as in sickle cell disease or hereditary spherocytosis), where excessive breakdown of RBCs leads to a large bilirubin load, and certain inherited disorders of bilirubin metabolism such as Gilbert’s or Crigler–Najjar syndrome. Unconjugated bilirubin may cause:

Jaundice: uBr diffuses into elastin-rich tissues like sclera and skin, causing yellow discolouration
Pigment gallstones: uBr precipitates with Ca²⁺ in the gallbladder, making calcium bilirubinate pigment gallstones
Normal stool/urine as uBr is not water-soluble (albumin-bound) so cannot enter urine/duodenum

A yellow gallbladder stone is most likely composed of what?

((Cholesterol::☑️ Cholesterol stones are typically yellow, often solitary, and associated with obesity and female sex))
((Calcium bilirubinate::Pigment stones are usually black or brown, not yellow))
((Bile salts::Not the primary structural component of gallstones))
((Calcium oxalate::Seen in renal stones, not gallbladder stones))
((Triglycerides::Not a constituent of gallstones))

A woman presents with right upper quadrant pain, jaundice, dark urine, and pale stools. What explains the dark urine?

((Increase in conjugated bilirubinuria::☑️ Conjugated bilirubin is water-soluble and excreted in urine in obstructive jaundice))
((Increase in unconjugated bilirubinuria::Unconjugated bilirubin is not water-soluble and is not excreted in urine))
((Increase in urea excretion::Does not cause dark urine in jaundice))
((Increase in urinary urobilinogen::Urobilinogen is reduced in obstructive jaundice))
((Reduced enterohepatic bile salt circulation::Explains pale stools but not dark urine))

A woman suffers with right upper quadrant pain, jaundice, dark urine, and offensive pale stools. What explains the steatorrhoea?

((Increase in conjugated bilirubinuria::Explains dark urine, not fat malabsorption))
((Increase in unconjugated bilirubinuria::Unconjugated bilirubin is not excreted in urine))
((Increase in urea excretion::Unrelated to steatorrhoea))
((Increase in urinary urobilinogen::Reduced in obstructive jaundice))
((Reduced enterohepatic bile salt circulation::☑️ Reduced delivery of bile salts to the intestine impairs fat emulsification))

💡 In pancreatitis, pancreatic lipase deficiency causes fat malabsorption leading to steatorrhoea. In obstructive jaundice (e.g. cholangitis), reduced delivery of bile salts to the intestine impairs fat emulsification, leading to steatorrhoea.

What explains offensive stools in obstructive jaundice?

((Increased conjugated bilirubin in the blood::Explains dark urine, not stool changes))
((Decreased conjugated bilirubin in the blood::Incorrect in obstructive jaundice))
((Decreased hepatic secretion of bile into the intestine::☑️ Lack of bile salts in the intestine impairs fat digestion causing steatorrhoea and offensive stools))
((None of the above::Correct mechanism is listed above))

Skin deposition of which of the following is responsible for itching in obstructive jaundice?

((Bile salts::☑️ Accumulation of bile salts in the skin stimulates nerve endings causing pruritus))
((Conjugated bilirubin::Conjugated bilirubin excreted in urine causes dark urine))
((Unconjugated bilirubin::Not responsible for pruritus))
((Urobilinogen::Not deposited in skin))
((Cholesterol::Not the cause of pruritus in cholestasis))

💡Normally, bile, which contains bile salts and conjugated bilirubin, enters the duodenum via the common bile duct. The bile salts emulsify lipids in the small intestine, facilitating the action of lipase. Gut bacteria convert conjugated bilirubin to stercobilin, the brown pigment that makes stool brown. Obstructive jaundice means bile cannot reach the gut via the CBD, i.e., there is decreased hepatic secretion of bile into the intestine. The mechanisms for the subsequent symptoms are:

↓ Bile salts in the gut → Lipids are not emulsified → Excess lipids in stool → Steatorrhea
↑ Bile salts in blood → Bile salts deposit in skin → Irritate cutaneous nerve endings → Pruritus
↓ conjugated Br in the gut → ↓ Stercobilin made in gut → Pale stool
↑ conjugated Br (water-soluble) in blood → Excess cBr excreted in urine → Dark urine

A 20-year‑old male presents with mild jaundice and pale stools. Which antibody is most likely positive?

((Anti-phospholipid::Antiphospholipid syndrome))
((Anti-endomysial::Coeliac disease))
((Anti-mitochondrial::Primary biliary cholangitis, typically occuring in middle-aged women))
((Anti-cardiolipin::Subtype of antiphospholipid antibodies, associated with antiphospholipid syndrome))
((ANCA::☑️ p-ANCA is associated with primary sclerosing cholangitis, which presents with cholestatic features in young males))

A 40-year-old man with IBD has bile duct strictures and beading on cholangiography. Diagnosis?

((Primary sclerosing cholangitis::☑️ Associated with IBD; multifocal strictures cause characteristic beading appearance))
((Primary biliary cholangitis::Affects small intrahepatic ducts and typically occurs in middle-aged women))
((Cholangiocarcinoma::May cause stricture but not the classic diffuse beading pattern))
((Choledocholithiasis::Causes focal obstruction, not multiple strictures with beading))

A 27-year-old man has 6 months of mild jaundice, dark urine, and mild itching. Diagnosis?

((Carcinoma of the duodenum::Carcinoma of the duodenum would usually present with obstructive jaundice and weight loss, uncommon at this age))
((Choledocholithiasis::Choledocholithiasis typically causes intermittent acute obstruction rather than chronic mild cholestasis))
((Gilbert syndrome::Gilbert syndrome causes unconjugated hyperbilirubinaemia without pruritus or dark urine))
((Hepatitis C::Hepatitis C usually presents with hepatocellular pattern rather than isolated cholestatic pruritus))
((Primary biliary cholangitis::☑️ Chronic cholestatic symptoms including pruritus, jaundice, and dark urine))