In a small number of people with gallstones, serious problems can develop if the gallstones cause a severe blockage or move into another part of the digestive system.

Inflammation of the gallbladder (acute cholecystitis)

In some cases of gallstone disease a bile duct can become permanently blocked, which can lead to a build-up of bile inside the gallbladder. This can cause the gallbladder to become infected and inflamed.

The medical term for inflammation of the gallbladder is acute cholecystitis. Symptoms include:

• pain in your upper abdomen that travels towards your shoulder blade (unlike biliary colic, the pain usually lasts longer than five hours)
• a high temperature (fever) of 38°C (100.4°F) or above
• a rapid heartbeat

An estimated one in seven people with acute cholecystitis will also experience jaundice (see below).

Acute cholecystitis is usually treated first with antibiotics to settle the infection and then keyhole surgery to remove the gallbladder. This operation can be more difficult when performed as an emergency and there is a higher risk of it being converted to an open procedure.

Sometimes a severe infection can lead to a gallbladder abscess (empyema of the gallbladder). Antibiotics alone do not always treat these and they may need to be drained.

Occasionally a severely inflamed gallbladder can tear, leading to peritonitis (inflammation of the thin layer of tissue that lines the inside of the abdomen, called the peritoneum). If this happens, you may need to have antibiotics given directly into a vein (intravenous antibiotics) and surgery may be required to remove a section of the peritoneum if part of it becomes severely damaged.

Jaundice

If a gallstone passes out of the gallbladder into the bile duct and blocks the flow of bile, jaundice occurs.

Symptoms of jaundice include:

• yellowing of the skin and eyes
• dark brown urine
• pale stools (faeces)
• itching

Sometimes the stone passes from the bile duct on its own. If it doesn’t, the stone needs to be removed. See treating gallstones.

Infection of the bile ducts (acute cholangitis)

If the bile ducts become blocked, they are vulnerable to infection by bacteria. The medical term for a bile duct infection is acute cholangitis.

Symptoms of acute cholangitis include:

• pain in your upper abdomen that travels towards your shoulder blade
• a high temperature
• jaundice
• chills
• confusion
• itchy skin
• generally feeling unwell

Antibiotics will help treat the infection, but it is also important to help the bile from the liver to drain with an endoscopic retrograde cholangio-pancreatography (ERCP). See treating gallstones for more information.

Acute pancreatitis

Acute pancreatitis may develop when a gallstone moves out of the gallbladder and blocks the opening (duct) of the pancreas, causing it to become inflamed.

The most common symptom of acute pancreatitis is a sudden severe dull pain in the centre of your upper abdomen, around the top of your stomach.

The pain of acute pancreatitis often gets steadily worse until it reaches a constant ache. The ache may travel from your abdomen and along your back and may feel worse after you have eaten. Leaning forward or curling into a ball may help to relieve the pain.

Other symptoms of acute pancreatitis can include:

• feeling sick
• being sick
• diarrhoea 
• loss of appetite
• a high temperature (fever) of 38°C (100.4°F) or above
• tenderness of the abdomen
• less commonly, jaundice

There is currently no cure for acute pancreatitis, so treatment focuses on supporting the functions of the body until the inflammation has passed.

This usually involves admission to hospital so you can be given fluids into a vein (intravenous fluids), pain relief, nutritional support and oxygen through tubes into your nose.

With treatment, most people with acute pancreatitis improve within a week and are well enough to leave hospital after 5-10 days.

Read more about acute pancreatitis.

Cancer of the gallbladder

Gallbladder cancer is a rare but serious complication of gallstones. An estimated 660 cases of gallbladder cancer are diagnosed in the UK each year.

Having a history of gallstones increases your risk of developing gallbladder cancer. Approximately four out of every five people who have cancer of the gallbladder also have a history of gallstones.

However, people with a history of gallstones have a less than one in 10,000 chance of developing gallbladder cancer.

If you have additional risk factors, such as a family history of gallbladder cancer or high levels of calcium inside your gallbladder, it may be recommended that your gallbladder be removed as a precaution, even if your gallstones aren’t causing any symptoms.

The symptoms of gallbladder cancer are similar to those of complicated gallstone disease, including:

• abdominal pain
• high temperature (fever) of 38°C (100.4°F) or above
• jaundice

Gallbladder cancer can be treated with a combination of surgery, chemotherapy and radiotherapy.

Gallstone ileus

Another rare but serious complication of gallstones is known as gallstone ileus. This is where the bowel becomes obstructed by a gallstone.

There were around 300 hospital admissions for gallstone ileus in England during 2012-13.

Gallstone ileus can occur when an abnormal channel, known as a fistula, opens up near the gallbladder. Gallstones are then able to travel through the fistula and can block the bowel.

Symptoms of gallstone ileus include:

• abdominal pain
• being sick
• swelling of the abdomen 
• constipation

A bowel obstruction requires immediate medical treatment. If it is not treated, there is a risk that the bowel could split open (rupture). This could cause internal bleeding and widespread infection.

If you suspect that you have an obstructed bowel, contact your GP as soon as possible. If this is not possible, phone NHS 111.

Surgery is usually required to remove the gallstone and unblock the bowel. The type of surgery you receive will depend on where in the bowel the obstruction has occurred.