Cholelithiasis refers to the presence of abnormal concretions (gallstones) in the gallbladder. About 10–20% of American adults have gallstones. Gallstones most commonly consist of cholesterol but may be pigmented (due to hemolysis or infection) or mixed. Cholelithiasis can manifest with biliary colic (postprandial RUQ pain) but is most commonly an incidental finding in asymptomatic individuals. The diagnosis is confirmed by ultrasound. Symptomatic cholelithiasis is managed with laparoscopic cholecystectomy.
|Disorders caused by gallstones|
|Cholelithiasis||Choledocholithiasis||Acute cholecystitis||Acute cholangitis|
|Laboratory findings|| |
|Diagnostic imaging|| |
|Treatment|| || |
- Imbalance in bile salts, lecithin (stabilizer), cholesterol, calcium carbonate, and bilirubin
- Biliary stasis is a key component in gallstone formation.
- Impaired gallbladder emptying (e.g., due to bowel rest, prolonged total parenteral nutrition, pregnancy; ) → biliary sludge → bile stasis (cholestasis)
Cholesterol stones 
- Obesity, insulin resistance, dyslipidemia
- Especially during reproductive years due to increased levels of estrogen and progesterone
- Increased estrogen levels cause increased secretion of bile rich in cholesterol, (lithogenic bile), which can result in the formation of cholesterol gallstones.
- Increased progesterone levels cause smooth muscle relaxation, decreased gallbladder contraction, and subsequent bile stasis with formation of gallstones.
- Multiparity or pregnancy
- Age (> 40 years of age)
- European, Native American, or Hispanic ancestry
- Family history
- Drugs: fibrates (inhibition of ), estrogen therapy, oral contraceptives
- Malabsorption (e.g., Crohn disease, ileal resection, cystic fibrosis)
- Rapid weight loss (e.g., after bariatric surgery)
- Pathophysiology: abnormal hepatic cholesterol metabolism → ↑ cholesterol concentration in bile and ↓ bile salts and lecithin → hypersaturated bile → precipitation of cholesterol and calcium carbonate → cholesterol stones or mixed stones
During pregnancy, increased estrogen levels cause increased secretion of lithogenic bile (rich in cholesterol), resulting in the formation of cholesterol gallstones. Increased progesterone levels cause smooth muscle relaxation, decreased and impaired gallbladder contraction, and subsequent bile stasis and formation of gallstones.
Rule of the 6 Fs: Fat, Female, Fertile, Forty, Fair-skinned, Family history.
Black pigment stones 
- Risk factors
- Pathophysiology: ↑ hemolysis → increase in circulating unconjugated bilirubin → increased uptake and conjugation of bilirubin → precipitation of bilirubin polymers and stone formation
Mixed/brown pigment stones 
- Risk factors: bacterial infections and parasites (e.g., Clonorchis sinensis, Opisthorchis species) in the biliary tract, sclerosing cholangitis 
- Pathophysiology: infection or infestation → release of β-glucuronidase (by injured hepatocytes and bacteria) → hydrolyzes conjugated bilirubin and lecithin in the bile → increased unconjugated bilirubin and fatty acids → precipitation of calcium carbonate, cholesterol, and calcium bilirubinate (dark color) in bile
- Most gallstones are asymptomatic.
- Biliary colic: constant, dull RUQ pain lasting < 6 hours
- Nausea, vomiting, early satiety
- Bloating, dyspepsia
Only a minority of patients with gallstones are symptomatic!
- Asymptomatic cholelithiasis : No diagnostic workup is required.
- Suspected symptomatic cholelithiasis
If appropriately trained, consider performing a.
- Indication: best initial test in suspected symptomatic cholelithiasis 
Characteristic findings 
- Cholelithiasis 
Biliary sludge 
- Low-level echogenic material in the dependent portion of the GB
- No posterior acoustic shadowing
- Slow movement with the changing of patient posture
- Accuracy: operator- and technique-dependent 
If appropriately trained, consider performing a biliary POCUS to rule in cholelithiasis. If the study is negative, further investigations (e.g., laboratory studies, RUQ ultrasound performed by a radiologist, additional imaging) may be necessary. 
Additional imaging studies
Additional imaging may be required if complications of cholelithiasis (e.g., acute cholecystitis, acute cholangitis, choledocholithiasis, biliary pancreatitis) cannot be ruled out, or to evaluate for other causes of abdominal pain.
- Supportive findings: well-defined hypointense (on T2) filling defect(s) within the gallbladder lumen 
CT abdomen with IV contrast 
- Supportive findings (of radiopaque stones): well-defined hyperdense structure(s) within the gallbladder lumen
- Indication: usually not indicated in the evaluation of cholelithiasis, but may be performed as part of the workup of acute abdominal pain
- Findings: gallstones with an outer radiopaque rim and radiolucent center 
- Disadvantages: similar to those of CT scan
- Abdominal (See also “Acute abdominal pain” and “Differential diagnosis of abdominal pain.”)
- See also “Differential diagnosis of acute abdomen.”
Differential diagnoses of intraluminal gallbladder wall pathology
- Cholangiocarcinoma (see biliary cancer)
- Definition: benign tumor of the gallbladder wall with low metastatic potential
- Diagnosis: Ultrasound (transabdominal or endoscopic)
The differential diagnoses listed here are not exhaustive.
- Asymptomatic cholelithiasis
- Symptomatic uncomplicated cholelithiasis
- Symptomatic complicated cholelithiasis
Initial supportive therapy of acute biliary disease 
- Bowel rest: NPO
- Analgesics 
- Spasmolytics (e.g., dicyclomine ): consider as adjuvant therapy with analgesics in patients with severe pain 
- Treatment for protracted vomiting
- Procedure: elective
- Symptomatic cholelithiasis
Asymptomatic cholelithiasis with any of the following:
- Increased risk of gallbladder cancer (e.g., gallbladder polyps, porcelain gallbladder, gallstones ≥ 3 cm) 
- Increased risk of developing complications (e.g., immunocompromised patients, multiple gallstones) 
- Increased risk of becoming symptomatic (e.g., hemolytic anemia, patients undergoing gastric bypass surgery) 
- Contraindication: suspected gallbladder cancer (see ''Treatment'' in “Biliary cancer”) 
- Preoperative precautions: Assess for (see '' in all symptomatic patientsDiagnosis of choledocholithiasis”). 
- Timing: as early as possible in uncomplicated symptomatic cholelithiasis 
- Complications: See “ ”.
Cholecystectomy is usually not indicated in asymptomatic cholelithiasis.
Nonoperative management of cholelithiasis 
- Patients at high risk of complications due to surgery or anesthesia (e.g., recent myocardial infarction)
- Patients unwilling to undergo surgery
Expectant management 
- Lifestyle modifications :
- Follow-up: if symptoms recur
Oral bile acid dissolution therapy
- May be useful in dissolving pure cholesterol stones (i.e., radiolucent stones) that are < 0.5 cm 
- Ursodeoxycholic acid (off-label)
- Duration of therapy: 6–24 months 
- Advantage: symptomatic improvement even if stones are not completely dissolved 
- Ineffective in mixed stones
- High recurrence rates 
- Long duration of therapy
- Requires repeat imaging to track treatment response
Extracorporeal shock wave lithotripsy (ESWL)
ESWL is also used in the .
- Definition: : a noninvasive method of stone fragmentation using an acoustic pulse in the treatment of gallstones and pancreatic stones
- Indication: typically used for solitary stones that can be localized well on imaging (radiolucent)
- Stones are localized using x-ray or ultrasound.
- A lithotriptor generates shock waves that are focused on the stone, fragmenting it in the process.
- Passage of stone fragments
- Advantage: is noninvasive: and can be performed on an outpatient basis 
- Commonly causes biliary colic
- Lower success rate in the presence of multiple stones
- Risk of injury to adjacent solid organs (rare)
- Prognosis: high recurrence rate (between 40 and 60% within 5 years) 
- Keep patient NPO.
- Provide analgesia, IV fluids, antiemetics). (e.g.,
- Obtain RUQ ultrasound or perform biliary POCUS if available.
- Identify and manage complications of cholelithiasis (e.g., acute cholecystitis, acute cholangitis, choledocholithiasis, biliary pancreatitis).
- Refer to general surgery for an elective cholecystectomy to prevent recurrence.
- Acute cholangitis
- Acute biliary pancreatitis
- Biliary-enteric fistula: Cholecystoenteric/choledochoenteric fistula (rare) , which can cause gallstone ileus (rare) 
Complications due to gallstone impaction at the gallbladder neck or infundibulum
Mirizzi syndrome 
- Definition: extrinsic compression of the common bile duct (or any extrahepatic bile duct) by gallstone(s) impacted in the cystic duct or the infundibulum of the gallbladder 
- Clinical features: similar to choledocholithiasis
- Diagnostics: preferably ERCP/MRCP
- Cholecystocholedochal fistula: an abnormal communication between the gallbladder and the common bile duct
- Cholecystoenteric/choledochoenteric fistula (biliary-enteric fistula): an abnormal communication between the gallbladder or the CBD with the adjacent bowel
- Gallstone ileus: due to biliary-enteric fistula
Gallbladder mucocele (gallbladder hydrops) 
- Definition: marked distention of the gallbladder with sterile mucinous content due to chronic biliary outflow obstruction
- Impacted gallstone at the gallbladder neck (most common)
- Resolved acute cholecystitis 
- Tumors at the gallbladder neck or CBD (e.g., GB polyps, cholangiocarcinoma, carcinoma of pancreatic head)
- Acute inflammatory conditions (e.g., Kawasaki disease)
- Extrinsic compression of the biliary outflow tract (e.g., lymphadenopathy, adhesions, strictures)
- Pathophysiology: chronic biliary outflow obstruction → resorption of bile and secretion of mucin by biliary mucosa → collection of mucinous secretion within the gallbladder with no outflow → gross distention of the gallbladder
- Clinical features: asymptomatic mass in the RUQ; no signs of infection
- Diagnostics: (preferably ultrasound or CT); show grossly distended fluid-filled gall bladder without signs of inflammation 
We list the most important complications. The selection is not exhaustive.