Gallstones

Definition/diagnostic criteria Gallstones (cholelithiasis) are the formation of solid particles or stones in the gallbladder. These stones can vary in size and composition, with cholesterol and pigment stones being the most common types. Diagnostic criteria for gallstones typically include clinical symptoms along with imaging studies to confirm their presence.

Epidemiology Gallstones are common. The prevalence of gallstones is estimated to be around 10-15% of the UK population however most cases remain asymptomatic. Risk factors for developing gallstones include:

• Crohn’s disease.
• Diabetes mellitus.
• Diet: Diets higher in triglycerides and refined carbohydrates and low in fibre are associated with gallstones.
• Female gender. 
• Genetic and ethnic factors.
• Increasing age.
• Medication (for example, somatostatin analogues, glucagon-like peptide-1 analogues and ceftriaxone).
• Non-alcoholic fatty liver disease.
• Prolonged fasting/weight loss.
• Use of hormone replacement therapy (HRT).

Diagnosis

Clinical features

The majority of cases are asymptomatic. The clinical presentation of gallstones can vary, but common symptoms include:

• Biliary colic: Intermittent, severe pain in the right upper abdomen, often triggered by a fatty meal. The pain can radiate to the back or right shoulder and typically lasts for a few hours.
• Nausea and vomiting: Patients may experience nausea and vomiting, especially during episodes of biliary colic.
• Jaundice: If a gallstone obstructs the common bile duct, it can lead to jaundice.
• Complications: In severe cases, gallstones can lead to complications such as acute cholecystitis or pancreatitis.

Investigations

• Ultrasound may confirm the diagnosis but the absence of visible stones does not exclude them
• Blood tests including serum bilirubin and liver function tests (gallstones in the common bile duct may result in abnormal LFTs)
• Consider referral for further investigations if results are normal but clinical suspicion remains high (e.g. if the common bile duct is dilated or liver function tests are abnormal). These may include Magnetic resonance cholangiopancreatography (MRCP) or Endoscopic Ultrasound (EUD).

Treatment

Asymptomatic gallstones: These do not require treatment, unless they are in the common bile duct as these may result in serious complications such as cholangitis and pancreatitis.

Symptomatic gallstones

• For intermittent mild to moderate pain, offer paracetamol or a nonsteroidal anti-inflammatory drug (NSAID).
• If pain cannot be managed in primary care refer to hospital as an emergency.
• For people who are systemically unwell arrange emergency admission.
• For people with jaundice or clinical suspicion of biliary obstruction (e.g. abnormal liver function tests) refer urgently.
• For all other people with symptomatic gallstone disease refer for consideration of laparoscopic cholecystectomy. Consider recommending a low-fat diet to help prevent biliary pain.

Prognosis Cholecystectomy typically leads to the resolution of symptoms and a low risk of recurrence. However, individuals with complications, such as choledocholithiasis or pancreatitis, may have a more complicated course and require additional interventions.