Gallstones and gallbladder disease explained

What gallstones are and why they form

The gallbladder stores bile made by the liver and squeezes it into the gut after meals to help digest fatty food. Bile contains cholesterol, bile salts, and a pigment called bilirubin. When the balance of these ingredients is upset — usually too much cholesterol — tiny crystals can form and slowly grow into stones, ranging from grains of sand to the size of a pebble. Several things raise the risk, often summarised as the "four Fs": being female, over forty, overweight (fatty), and having had children (fertile), though these are only rough guides. Rapid weight loss, some medical conditions, and family history also play a part. Most gallstones are made largely of cholesterol.

Symptoms: from silent stones to biliary colic

Many gallstones cause no symptoms at all and are found by chance on a scan; these "silent" stones usually need no treatment. Problems begin when a stone temporarily blocks the outlet of the gallbladder. This causes biliary colic — a severe, steady pain in the upper right or middle of the abdomen, often after a fatty meal, that can spread to the back or right shoulder blade and may come with nausea. Despite the name "colic", the pain is usually constant rather than gripping, and typically lasts from minutes to a few hours before easing. Between attacks, people often feel completely well. Recurrent biliary colic is the most common reason gallstones come to medical attention.

When gallstones become dangerous

Sometimes a blockage does not clear, and complications develop. If the gallbladder becomes inflamed and infected (acute cholecystitis), the pain becomes prolonged and severe, often with fever and tenderness, and needs hospital treatment. If a stone slips into the main bile duct, it can block bile draining from the liver, causing jaundice (yellowing of the skin and eyes), dark urine, and pale stools. A blocked duct can also become infected (cholangitis), a serious emergency, or trigger inflammation of the pancreas (acute pancreatitis), which causes severe upper abdominal pain radiating to the back. These complications are why persistent severe abdominal pain, fever, or jaundice should always be assessed urgently rather than managed at home.

How gallstones are diagnosed

The first and most useful test is an abdominal ultrasound scan, which is painless and reliably shows stones in the gallbladder and any thickening of its wall. Blood tests check for signs of infection, inflammation, and problems with the liver and pancreas, helping to spot complications. If doctors suspect a stone in the main bile duct, more detailed imaging such as an MRI scan of the bile ducts (MRCP) may be arranged. In some cases a procedure called ERCP, which uses an endoscope passed through the mouth, is used both to look at and to clear stones from the bile duct. The choice of tests depends on the symptoms and how unwell someone is.

Treatment and surgery

Silent gallstones causing no symptoms are usually left alone. Once gallstones cause pain or complications, the standard treatment is to remove the gallbladder in an operation called a cholecystectomy, almost always done by keyhole (laparoscopic) surgery. Removing the gallbladder is safe and effective, and the body copes well without it — bile simply flows directly from the liver into the gut. Most people recover within a couple of weeks and can eat normally, though some notice looser stools initially. In the meantime, eating a lower-fat diet can reduce attacks, and pain relief helps during episodes. If a stone is stuck in the bile duct, it is often cleared by ERCP before or around the time of surgery.