01OverviewDefinition, clinical context and the essential points that orientate the chapter.
Choledocholithiasis means one or more calculi within the common bile duct. Stones usually migrate from the gallbladder, although primary duct stones can form in stasis or infection. Obstruction may be intermittent: bilirubin and pain can fluctuate as a stone moves, and a transient marked transaminase rise can precede a more obviously cholestatic pattern. Complete obstruction produces jaundice, dark urine, pale stools and itch.
The clinical priority is to separate sterile obstruction from ascending infection. Fever and rigors, right-upper-quadrant pain and jaundice are a classic pattern, but severe cholangitis may present mainly with organ dysfunction. An afebrile jaundiced patient still needs timely investigation, and painless progressive obstruction with weight loss raises concern for pancreatic, ampullary or biliary cancer. A history of cholecystectomy does not exclude retained or recurrent duct stones.
NICE sequences tests deliberately. Liver tests and ultrasound come first. If ultrasound has not shown a duct stone but the duct is dilated or liver tests are abnormal, MRCP is considered; EUS follows when MRCP does not establish the diagnosis. ERCP exposes the patient to pancreatitis, bleeding, perforation, infection and sedation risk, so its value is strongest when intervention is expected. Duct clearance may be achieved surgically or by ERCP, followed by gallbladder surgery where appropriate.
Key points
- Consider choledocholithiasis when jaundice or cholestatic liver tests accompany gallstone symptoms, pancreatitis or a dilated common bile duct.
- Begin with liver tests and ultrasound, noting that ultrasound may show duct dilatation without visualising the causative stone.
- Use MRCP when ultrasound is negative for duct stones but the common duct is dilated or liver tests are abnormal.
- Consider EUS if MRCP is non-diagnostic and suspicion remains, particularly for small distal stones.
- Reserve ERCP for a therapeutic purpose such as stone extraction, sphincter intervention or drainage rather than routine diagnosis.
- After duct clearance, offer laparoscopic cholecystectomy when gallbladder stones remain and the patient is fit, because the gallbladder continues to seed recurrent events.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Migrated gallbladder stones
Most common-duct calculi originate in the gallbladder and pass through the cystic duct, with smaller stones more able to migrate.
Primary duct stones
Bile stasis, infection, strictures or altered anatomy can permit calculi to form within ducts, including after cholecystectomy.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Mechanical cholestasis
A stone blocks bile flow, raising intraductal pressure and sending conjugated bilirubin into blood and urine.
- 2Bacterial ascent
Obstruction removes normal flushing and permits enteric organisms to proliferate, causing cholangitis and potentially septic shock.
- 3Ampullary interference
A distal stone may obstruct the shared pancreatic outflow and initiate acute pancreatitis, even if it later passes.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Rising conjugated bilirubin and alkaline phosphatase support impaired bile flow, while a moving stone can initially cause a sharp aminotransferase increase.
Scleral or skin icterus, dark urine, pale stools and pruritus suggest clinically significant cholestasis but do not identify its cause.
Rigors, fever, haemodynamic change or confusion convert a duct-stone work-up into urgent cholangitis management.
An ampullary stone can trigger pancreatic inflammation and then pass, leaving transient liver abnormalities without persistent duct dilatation.
Progressive painless jaundice, weight loss or new-onset diabetes requires assessment for pancreaticobiliary cancer even when gallstones coexist.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Liver blood testsFirst step - Why
- Determine whether biochemical cholestasis supports duct obstruction.
- Interpretation and limitations
- Interpret bilirubin, alkaline phosphatase and aminotransferases as a trajectory. Normal values reduce but do not eliminate the probability of an intermittently obstructing stone.
- 02
Transabdominal ultrasound - Why
- Look for gallbladder calculi and common-duct dilatation.
- Interpretation and limitations
- Direct stone visualisation is helpful, but distal duct stones may be hidden by bowel gas; a non-dilated duct does not absolutely exclude a recently migrated stone.
- 03
Magnetic resonance cholangiopancreatography - Why
- Map the duct non-invasively when initial tests leave suspected choledocholithiasis.
- Interpretation and limitations
- MRCP shows filling defects and anatomy without ERCP complications, but very small distal stones or motion artefact can produce uncertainty.
- 04
Endoscopic ultrasound - Why
- Resolve persisting suspicion after non-diagnostic imaging.
- Interpretation and limitations
- EUS is sensitive for small duct stones and ampullary lesions, yet it is invasive and usually diagnostic rather than a means of duct clearance.
- 05
Therapeutic ERCP - Why
- Drain bile and remove or bypass an obstructing stone.
- Interpretation and limitations
- Plan cannulation, sphincter therapy, extraction or stenting with appropriate consent. Failure or altered anatomy requires surgical or percutaneous alternatives, not repeated unplanned procedures.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Malignant obstruction
Pancreatic, ampullary, gallbladder or cholangiocarcinoma can cause progressive jaundice, weight loss and duct dilatation without calculi.
Drug-induced cholestasis
Antibiotics, anabolic agents and other medicines can produce jaundice with no mechanical blockage; medication timing and imaging separate the mechanisms.
Acute hepatitis
Hepatocellular injury usually causes proportionately greater aminotransferase elevation, but early migrating stones can mimic this pattern.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01Worked case: probable duct stoneSelect the next testFirst stepAn adult with episodic biliary pain has bilirubin 58 micromol/L and a 9 mm common bile duct on ultrasound, but no duct stone is seen and there is no fever or organ dysfunction.+
- 1Recognise a substantial probability of choledocholithiasis while confirming that acute cholangitis is not currently present.
- 2Request MRCP to define duct anatomy because ultrasound is negative for a stone but liver tests and duct calibre remain abnormal.
- 3If a stone is confirmed, arrange therapeutic clearance by ERCP or a surgical pathway and plan subsequent cholecystectomy if gallbladder stones remain.
- 4EscalationVerify that bilirubin and symptoms are monitored while awaiting imaging and escalate immediately if fever, rigors, hypotension or confusion develops.
02Septic obstructionPrioritise drainageA jaundiced patient develops rigors and hypotension.+
- 1Start ABCDE resuscitation and obtain cultures without delaying antimicrobials.
- 2If this adult meets high-risk sepsis criteria, give broad-spectrum intravenous antibiotics within one hour of the initial emergency-department NEWS2 score or ward deterioration; use the named medicine-card regimen only where the local protocol and patient factors fit.
- 3Contact an experienced ERCP service urgently for decompression, using percutaneous or operative drainage if endoscopy cannot provide timely control.
- 4Confirm perfusion and biochemical response after drainage, send bile for culture, and at 48–72 hours narrow, switch or stop treatment within the planned 5–7-day total course according to source control and microbiology.
03Negative MRCPResolve remaining probabilityMRCP is negative but bilirubin fluctuates and ultrasound showed a dilated duct.+
- 1AlternativeRecheck the clinical course and alternative causes of cholestasis.
- 2Discuss EUS for small distal stones or ampullary disease when the result would alter intervention.
- 3Avoid diagnostic ERCP unless the therapeutic likelihood justifies its complications.
- 4Document the threshold for renewed imaging or drainage if jaundice or sepsis recurs.
Key medicines and prescribing safety1 treatment · regimens, roles and cautions+
Co-amoxiclav only when duct obstruction is infected: current DBTH adult example
If an adult with choledocholithiasis has acute cholangitis and is covered by the Doncaster and Bassetlaw Teaching Hospitals September 2025 protocol, give co-amoxiclav 1.2 g intravenously every 8 hours. Review at 48–72 hours and, after effective drainage with clinical improvement and reliable absorption, switch to 625 mg orally every 8 hours; total treatment is 5–7 days according to severity, progress and cultures. Under the same DBTH acute cholecystitis/cholangitis protocol, if the patient is older than 65 years AND received co-amoxiclav or a cephalosporin in the preceding 2 weeks, use piperacillin/tazobactam 4 g/0.5 g (4.5 g) by intravenous infusion every 8 hours instead, then de-escalate to an appropriate oral antibiotic from cultures or Infection Team advice; the same 5–7-day total course is governed by severity and progress.Avoid in penicillin hypersensitivity or previous co-amoxiclav-associated jaundice or hepatic dysfunction. Check renal function: the current 1,000/200 mg intravenous SmPC uses an initial 1,000/200 mg then 500/100 mg every 12 hours for creatinine clearance 10–30 mL/min, or every 24 hours below 10 mL/min; seek pharmacy advice for oral dosing and the local allergy alternative. Review blood and bile cultures and do not let antimicrobials delay decompression. For piperacillin/tazobactam, the current SmPC specifies infusion over 30 minutes, no renal change above 40 mL/min, 4 g/0.5 g every 8 hours as the maximum at creatinine clearance 20–40 mL/min, and 4 g/0.5 g every 12 hours below 20 mL/min. Avoid it after penicillin hypersensitivity or a severe immediate reaction to another beta-lactam.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Ascending cholangitis
Infection behind an obstructed common bile duct can progress rapidly to bacteraemia, hypotension, encephalopathy and multiorgan failure unless bile is decompressed.
Acute pancreatitis
A calculus lodged at the ampulla can obstruct pancreatic outflow, activating inflammation that may progress to necrosis, fluid collections or organ failure.
Secondary biliary injury
Prolonged obstruction can cause vitamin malabsorption, coagulopathy and hepatic injury while untreated stents can occlude and reinfect.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Trend bilirubin, alkaline phosphatase and aminotransferases after suspected passage or intervention.
- Observe temperature, blood pressure, mental state and urine output for evolution into cholangitis.
- After ERCP, monitor for new epigastric pain, bleeding, fever or perforation and check tests according to the clinical picture.
- Confirm documented duct clearance or a stent follow-up plan; temporary stents need named removal or exchange responsibility.
- Arrange cholecystectomy after clearance when indicated and verify that recurrent symptoms have not been lost between services.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
A moving stone changes tests
Intermittent obstruction explains fluctuating pain and biochemistry, so a single normal bilirubin cannot reconstruct the whole episode.
Dilatation is indirect evidence
A widened duct increases suspicion but can persist after a stone passes and may reflect age, previous surgery or another obstruction.
ERCP is an intervention
Its pancreatitis and bleeding risks are justified by likely therapy, not by convenience as a diagnostic image.
Clearance has two targets
Removing a duct stone treats present obstruction; removing a symptomatic stone-bearing gallbladder reduces future migration.
11Common pitfallsFrequent interpretation and management errors.
- 01
Using normal temperature to exclude duct stones or early infection.
- 02
Calling all jaundice gallstone-related without assessing cancer and drug or liver causes.
- 03
Proceeding straight to diagnostic ERCP when MRCP or EUS would refine probability.
- 04
Failing to arrange stent removal or gallbladder treatment after an apparently successful emergency procedure.