Yes, it is technically possible to vomit up a gallstone, but it’s extremely rare. For a gallstone to travel from the gallbladder into the stomach or upper intestine where it could be expelled through vomiting, an abnormal connection called a fistula has to form between the gallbladder and the digestive tract. This doesn’t happen during a typical gallbladder attack. It’s a complication of long-standing gallstone disease, and when it does occur, it usually signals a serious medical situation.
How a Gallstone Reaches the Stomach
Under normal circumstances, your gallbladder connects to the digestive system only through a narrow duct that drains bile into the upper small intestine (the duodenum). A gallstone sitting in your gallbladder has no direct path to your stomach. It can’t simply float up and come out.
For a gallstone to become something you could vomit, chronic inflammation from repeated gallbladder attacks has to erode through the gallbladder wall and into a neighboring section of the digestive tract. This creates an abnormal tunnel, or fistula, between the two organs. These fistulas develop in roughly 3% to 5% of people with gallstones, making them an uncommon but recognized complication. Once a fistula opens, a gallstone can pass directly from the gallbladder into the duodenum or, less commonly, the stomach itself.
Bouveret Syndrome: When a Stone Gets Stuck
The condition most closely linked to vomiting and gallstones is called Bouveret syndrome. In this scenario, a large gallstone passes through a fistula into the duodenum and gets lodged there, blocking the outlet of the stomach. The classic symptom triad is upper abdominal pain, nausea, and vomiting. About 85% of patients experience nausea and vomiting, and 70% have significant abdominal pain. Symptoms often come and go, waxing and waning as the stone shifts position.
In rare cases, the stone itself is actually expelled in the vomit. This is documented in the medical literature but is far less common than the persistent vomiting caused by the blockage. Some patients also experience blood in their vomit if the stone erodes into nearby blood vessels. Over time, the obstruction can lead to dehydration, weight loss, and an inability to keep food down.
Bouveret syndrome tends to affect older adults with a long history of gallbladder problems. Because the symptoms overlap with many other digestive conditions, it’s frequently missed on initial evaluation. Standard X-rays only identify it about 21% of the time, and even CT scans catch it in roughly 60% of cases.
Stone Size Determines What Happens
Not every gallstone that enters the intestine causes a blockage. Stones smaller than about 2 centimeters (roughly three-quarters of an inch) typically pass through the entire digestive tract and come out in stool without causing symptoms. You’d likely never know it happened.
The stones that cause problems, including the kind involved in Bouveret syndrome, are usually around 4 centimeters (about 1.5 inches) in diameter. Anything 2.5 centimeters or larger is considered prone to getting stuck. These are predominantly cholesterol-based stones that have been growing in the gallbladder for years. A stone that large can’t easily navigate the twists and narrow passages of the intestine, so it lodges in place and creates a blockage.
What Treatment Looks Like
If a gallstone is blocking your stomach outlet or upper intestine, it needs to be removed. In some cases, doctors can reach the stone through an endoscopic procedure, threading a flexible scope down through the mouth and into the digestive tract to break up or extract the stone without surgery. This approach avoids incisions entirely.
When endoscopy isn’t sufficient, surgery is required to remove the impacted stone and, in many cases, the gallbladder itself. Gallbladder removal is a routine procedure, typically done laparoscopically through two or three small incisions. Most people recover quickly and live normally without a gallbladder. If a fistula is present, the surgeon may repair it at the same time, though the approach depends on the patient’s overall health and the complexity of the situation.
Vomiting With Gallstones Is Usually Something Else
If you have gallstones and you’re vomiting, the far more likely explanation is a standard gallbladder attack. When a stone temporarily blocks the duct that drains bile, it causes intense upper abdominal pain (called biliary colic) that commonly triggers nausea and vomiting. This is your body reacting to the pain and the disrupted digestion, not a stone traveling upward. The stone stays in the gallbladder or bile duct system.
The distinction matters. Biliary colic episodes are painful but usually resolve within a few hours as the stone shifts. Bouveret syndrome and related fistula complications cause persistent or worsening symptoms over days, including an inability to eat, progressive bloating, and sometimes vomiting that won’t stop. If vomiting from a gallbladder-related cause persists beyond a typical attack, that’s a signal something more complex may be going on.