AuthorisedTherapeutic use (Phase IV)Interventional

Cholesterol lowering with atorvastatine for the prevention of gallstones following bariatric surgery (CHOLSTONE): an investigator- blinded randomised controlled trial

This research trial, called CHOLSTONE, is investigating whether a widely used medicine called atorvastatin can help prevent gallstones in patients who have recently undergone bariatric (weight-loss) surgery. Gallstones can be a common issue after this type of surgery. The study aims to find out if taking atorvastatin reduces the chance of developing gallstones within six months of the operation. Researchers will use ultrasound scans to check for gallstones. They will also track changes in cholesterol levels and how the medicine affects the body, as well as checking for any side effects. This study is for adults over 18, both men and women.

At a glance

Status

Authorised

Phase

Therapeutic use (Phase IV)

Sponsor

Spaarne Gasthuis Stichting

Enrolment target

202

Start

17 Mar 2026

Gallstones (chole(cysto)lithiasis) following bariatric surgery

What is this study about?

When people have weight-loss surgery, their bodies go through many changes. One common side effect that can develop afterwards is the formation of gallstones. Gallstones are small, hard deposits that can form in the gallbladder, a small organ under your liver. They can sometimes cause pain or other problems.

This study, named CHOLSTONE, aims to see if a commonly prescribed medication called atorvastatin can help reduce the chance of developing these gallstones after weight-loss surgery. Atorvastatin is a medication usually used to lower cholesterol levels in the blood. Researchers are interested to see if it also has a benefit in preventing gallstones in this specific group of patients.

By carefully studying a group of patients, some of whom will take atorvastatin and some who won't (or will take a dummy pill), the researchers hope to understand if this medicine is an effective way to prevent gallstones after weight-loss surgery. The main way they will check this is by looking for gallstones using an ultrasound scan six months after the surgery.

Key takeaways

This study investigates if atorvastatin can prevent gallstones after weight-loss surgery.
Participation involves taking a medication and having an ultrasound check-up.
The study lasts for six months after your surgery.
You won't know if you're taking the active drug or a dummy pill.
It's for adults (18+) who have recently had weight-loss surgery.

Who may be eligible?

To be able to take part in this study, you would need to be an adult, meaning you are 18 years or older. This study is open to both men and women.

The most important thing is that you recently had bariatric, or weight-loss, surgery. The study is specifically looking at preventing gallstones that can happen after this type of surgery.

There might be other specific health conditions or medications that would mean you couldn't take part, but these details would be discussed with you by the study team.

Quick self-check

Are you 18 years old or older?
Have you recently had weight-loss (bariatric) surgery?
Are you comfortable taking a study medication for six months?
Are you willing to have an ultrasound scan?

This is a guide only — the research team will confirm whether you can take part.

What does participation involve?

If you decide to take part in this study, you would be asked to take a specific medication (either atorvastatin or a dummy pill) for a period of time after your weight-loss surgery. You wouldn't know if you were getting the active medicine or the dummy pill.

During the study, you would likely have a few appointments. The main check-up would be around six months after your surgery. At this appointment, you would have an ultrasound scan to see if you have developed any gallstones. You would also have blood tests to measure your cholesterol levels and understand how your body is handling certain substances.

Researchers will also carefully monitor you for any side effects from the medication. The total duration of your active participation in the study, including taking the medicine and having your follow-up checks, would be six months after your surgery.

Potential risks and benefits

Taking part in this study might offer the potential benefit of helping to find a way to prevent gallstones for people who have had weight-loss surgery. If you receive atorvastatin, it could also help improve your cholesterol levels. However, as with any medication, there's always a possibility of side effects from atorvastatin. The study team will monitor you closely for any issues and will discuss all known potential risks with you in detail. You are always free to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (1)

—
Netherlands

Common questions

What are gallstones?

Gallstones are small, hard deposits that can form in your gallbladder, which is a small organ located under your liver. They can sometimes cause discomfort.

What is atorvastatin?

Atorvastatin is a medicine commonly prescribed to lower high cholesterol levels in the blood. In this study, we're exploring if it can also help prevent gallstones after weight-loss surgery.

Will I know if I'm getting the active medicine or a dummy pill?

No, this is a 'blinded' study, meaning neither you nor your study doctor will know whether you are receiving atorvastatin or a dummy pill. This helps ensure the study results are fair and accurate.

How long will I need to be in the study?

Your active participation in the study, including taking the medicine and having your main checks, will last for six months after your weight-loss surgery.

What is an ultrasound scan?

An ultrasound scan is a safe and painless test that uses sound waves to create images of the inside of your body, allowing doctors to look for gallstones.