Gallstones are hard deposits that develop in the gallbladder, a small organ in the upper right abdomen just below the liver. They can range from so tiny they’re barely visible to as big as a golf ball. They can exist individually or by the hundreds.
In fact, in the normal population, 10% to 20% of Americans have gallstones and don’t even know it. The majority will never know it because they are asymptomatic — meaning they have no symptoms. The ones who will know they have gallstones often find out the hard way — through painful, often excruciating symptoms.
Gallstone Risk Factors
Although gallstones are common, there are some factors that might increase your risk. They include:
- Being female.
- Being 40 or older.
- Obesity or being overweight.
- Being sedentary.
- Being Native American or Hispanic of Mexican origin.
- Being pregnant.
- Eating a high-fat diet.
“Obesity carries with it a higher the risk of gallstones,” says Bestoun Ahmed, MD, an expert in bariatric surgery and obesity medicine at UPMC Magee-Womens Hospital.
Why Do Gallstones Form?
Gallstones form when bile, a fluid that aids fat digestion, contains too much cholesterol or bilirubin and not enough bile acids or lecithin — substances that allow water- and oil-based liquids to mix. Most gallstones are cholesterol gallstones, but pigment gallstones, which come from bilirubin, also are common.
“People with obesity have a much higher concentration of cholesterol in their bile,” explains Dr. Ahmed. “This leads to a nidus for stone formation in the gallbladder.”
In the long run, losing excess weight can help people with obesity lower their risk of developing gallstones. However, while in the process of rapid weight loss, gallstones can develop for the same reasons as obesity — it alters the balance of cholesterol, lecithin, and bile acids, and affects gallbladder function.
“Additionally, during rapid weight loss, hypotonia of the gallbladder can make it function poorly, so bile stays in it, gets stagnant, crystallizes, and forms stones,” Dr. Ahmed says. “As more cholesterol is getting excreted, the bile becomes super-saturated and the gallbladder emptying being less effective, leading to stones.”
People who have had bariatric surgery are leading candidates for gallstones because they tend to lose a significant amount of weight in the first three to six months. Gallstones are such a common occurrence after bariatric surgery that most providers routinely prescribe chenodeoxycholic acid in pill form for six months after surgery to prevent stone formation or keep existing stones from getting bigger. Using medication, risk of gallstone formation falls from 27% of bariatric surgery recipients to just 5%.
Gallstones and Obesity
Because gallstones are so common with obesity, you can deal with them before, during, or after weight loss surgery. Years ago, when a person had gallstones, a surgeon would have removed their entire gallbladder automatically. People can live without their gallbladders with no long-term consequences.
Nowadays, though, asymptomatic gallstones usually are left alone, and the vast majority of people who have them take them to their graves with no symptoms. “A decade’s worth of studies have shown that, when asymptomatic gallstones are left in place, only 7% ever become symptomatic,” says Dr. Ahmed.
If a stone becomes stuck in the gallbladder duct, however, the whole gallbladder may need removal.
Sometimes, gallbladder removal can happen at the same time as weight loss surgery, but adding the removal of the gallbladder poses a higher post-surgical risk of complications to some patients.
“For example, if there is a leak from the gallbladder duct after surgery, it would be hard to tell whether the leak is from the bariatric surgery or the gallbladder surgery,” says Dr. Ahmed. “So in most cases, if there are no symptoms, we leave the gallbladder alone. If the person develops symptoms afterwards, it can be taken out later.”
One catch, however: Some weight loss procedures — such as gastric bypass – change the pathway of the intestine. This altered pathway makes it a little trickier to remove a gallstone that has slipped into and obstructed the main bile duct.
“In a normal anatomy, the main bile duct stones could be fished out endoscopically through the mouth with no surgery,” Dr. Ahmed says. “But not in people who’ve had gastric bypass, because they don’t have that normal route. It takes the special expertise of a bariatric surgeon to access the duodenum to remove the main bile duct stones.”
How to Prevent Gallstones During Weight Loss
If you’re prepping to have bariatric surgery and want to know how you can lose weight and prevent gallstones, here are some measures you can take in advance. Dr. Ahmed advises that the best way to prevent gallstones, obesity, and significant metabolic problems is to:
- Eat a well-rounded diet that’s low in saturated fat.
- Drink 64 ounces of water per day.
- Exercise at least 150 minutes per week — and walking is fine!
- Get at least seven hours of uninterrupted sleep per night.
Fighting Obesity
Nationally, in 2022, 41.9% of adults were obese. Black adults had the highest levels of adult obesity at 49.9%, followed by Hispanic adults with an obesity rate of 45.6%, and white adults with a rate of 41.4%.
“Obesity is a multisystem disease — it affects every organ in the body,” says Dr. Ahmed. “Obesity can take down the whole system. Weight loss can improve not only gallstones but many other chronic problems.”
So whether you are looking to fight obesity with meal replacements, dietary management, medication, or bariatric surgery, any substantial weight loss plan can improve your health.
Talk to your primary care provider, cardiologist, pulmonologist, orthopaedic surgeon, or obesity medicine specialist if you think you can benefit from weight loss or weight loss surgery. For more information about metabolic and bariatric surgery, visit the website for the Minimally Invasive Bariatric and General Surgery Program of UPMC Magee-Womens Hospital.