GLP-1 drugs such as semaglutide (sold as Ozempic and Wegovy) slow down how fast the stomach empties food into the gut, a change doctors call delayed gastric emptying.
In rare cases, this can allow a gastric bezoar to form: a hard lump of undigested material that gets stuck in the stomach.
A 63-year-old woman on semaglutide developed a gastric bezoar and recovered after being given diet cola instead of surgery.
Ongoing vomiting, stomach pain, or inability to keep food down while on a GLP-1 drug needs prompt medical attention, not home treatment.
The 63 years old patient, lived in Massachusetts, suffered from type 2 diabetes and obesity. She had been receiving semaglutide for one year and lost around 18 kg (40 lbs). A month prior to the appointment she developed symptoms of nausea, vomiting, and burning pain in the upper right region of the abdomen.
The 63-year-old patient, who lived in Massachusetts, had type 2 diabetes and obesity. She had been receiving semaglutide for one year and lost around 18 kg (40 lb). About one month before seeking medical care, she developed nausea, vomiting, and burning pain in the upper right region of the abdomen.
A CT scan showed mildly dilated bile ducts and thickened material within the stomach. A subsequent magnetic resonance cholangiopancreatography (MRCP) confirmed the bile duct dilation but initially interpreted the stomach finding as trapped air. However, upper endoscopy later revealed that the stomach mass was actually a gastric bezoar.
A gastric bezoar is a solid lump, usually of undigested food, that collects in the stomach instead of passing through normally.
Instead of moving into the intestine, undigested food can remain in the stomach long enough to gradually compact into a firm mass, particularly when stomach emptying is slowed.
The most common type is a phytobezoar, formed from plant fibers in foods such as persimmons, pineapples, raisins, or celery. It is found in fewer than 1 in 200 upper endoscopies, making it a rare finding.
Common symptoms overlap with everyday stomach problems, including pain, bloating, nausea, and vomiting, so it is often missed at first.
Known risk factors include:
Previous stomach surgery, such as bariatric (weight-loss) surgery
Nerve damage that slows the stomach's normal movement
Any medication that slows gastric emptying, including GLP-1 drugs
Persimmons carry an extra twist. They contain a soluble tannin called shibuol, which reacts with stomach acid and hardens into an especially dense mass called a diospyrobezoar. This is why unripe persimmons get singled out more often than other high-fiber foods.
GLP-1 receptor agonists work partly by
slowing gastric emptying, keeping food in the stomach longer so a person feels full.
In rare situations, this same effect can allow undigested material to build up into a bezoar.
In this case, doctors stopped the semaglutide and considered it the likely cause.
This is based on a single case report, which describes what happened to one patient. It does not prove that GLP-1 drugs commonly cause bezoars, and larger studies would be needed to know how often this actually happens.
A second case report was published separately in December 2025, involving a 65-year-old woman taking a low dose of semaglutide weekly for six months without having ever been diabetic or undergone any stomach surgery, developing a phytobezoar in her body which migrated to the small intestine and formed a blockage. In contrast to the case in Massachusetts, she required surgery to remove the phytobezoar. The two cases individually do not imply a common risk, but they raise an issue of caution.
Cola-based drinks have been used for over 20 years as a first-choice treatment for phytobezoars, often avoiding the need for surgery.
Because the patient had diabetes, doctors chose diet cola instead of regular cola to avoid additional sugar while using the same carbonated, acidic treatment approach described in previous studies.
The usual protocol is 3 litres of cola, drunk or given through a feeding tube, over about 12 hours.
Doctors are not fully certain why it works. Cola is both acidic and carbonated (fizzy), and one or both of these properties are believed to help break down the fibrous material.
A review of published cases found cola worked on its own in about half of cases, and worked in combination with an endoscopy procedure in over 90 percent of cases.
That success rate drops for persimmon-related diospyrobezoars: the same review found cola alone dissolved about 61 percent of typical phytobezoars, but only about 23 percent of diospyrobezoars, since their tannin-hardened structure resists breaking down.
Cola dissolution is preferred over surgery or scope-based removal as a first step, since it costs less and carries a lower risk of complications.
Because this patient had diabetes, doctors used diet cola to avoid added sugar, cutting her dose to 1.5 litres instead of 3 since she disliked carbonated drinks. By the second day she reported a tugging sensation in her abdomen, after which her symptoms began to improve. A repeat endoscopy confirmed the bezoar was gone, and she went home symptom-free without restarting semaglutide.
Seek medical care promptly for:
Vomiting that doesn't stop for more than a day or two
Inability to keep food or fluids down
Worsening abdominal pain, especially spreading to the back
Signs of dehydration: dizziness, very dark urine, or passing very little urine
Faster-than-expected unintended weight loss
Don't self-treat with cola or soda at home. Here, cola was hospital-supervised, decided only after scans and endoscopy confirmed the bezoar. This calls for extra care in people with diabetes on medication, kidney disease, or heart conditions, who should always get sudden GI symptoms checked rather than managed at home.
No. Cola dissolution is a specific hospital treatment given only after endoscopy confirms a bezoar, usually continued under monitoring. Drinking soda at home won't diagnose or treat unworked-up stomach pain, and this case isn't a green light for treating everyday indigestion or acidity with diet soda.
There's a safety reason behind that: cola dissolution is designed for a bezoar still in the stomach. Once it moves into the narrow small intestine, doctors generally don't rely on cola, and surgery becomes safer. Drinking soda for undiagnosed pain, without knowing whether or where a blockage exists, risks delaying the treatment actually needed.
A gastric bezoar is a rare but real complication tied to GLP-1 drugs like semaglutide, driven by the same slowed digestion that helps with weight loss. Persimmons, pineapples, raisins, and celery add to the risk, persimmons especially so. Most cases resolve without surgery, sometimes with supervised cola, but this remains a doctor-directed treatment for a confirmed diagnosis, not a home remedy. Anyone on a GLP-1 medicine with ongoing vomiting or stomach pain should get checked out promptly.
Crane, Matthew A., Nicholas G. Economos, Anand Vaidya, Caroline M. Apovian, and Nicolette J. Rodriguez. "A Fizzy Fix." New England Journal of Medicine 393, no. 12 (September 25, 2025): e20. https://doi.org/10.1056/NEJMimc2502450.
Ladas, S. D., K. Triantafyllou, C. Tzathas, et, al. "Gastric Phytobezoars May Be Treated by Nasogastric Coca-Cola Lavage." European Journal of Gastroenterology & Hepatology 14, no. 7 (2002): 801–803. https://doi.org/10.1097/00042737-200207000-00017.
Ladas, S. D., D. Kamberoglou, G. Karamanolis, J. Vlachogiannakos, and I. Zouboulis-Vafiadis. "Systematic Review: Coca-Cola Can Effectively Dissolve Gastric Phytobezoars as a First-Line Treatment." Alimentary Pharmacology & Therapeutics 37, no. 2 (2013): 169–173. https://doi.org/10.1111/apt.12141.
Keng, C., S. M. Thor, R. Balasubramaniam, and F. Pretorius. "A Case Report of Bezoar-Induced Small Bowel Obstruction: A Potential Surgical Complication of Semaglutide." Cureus 17, no. 12 (2025): e99664. https://doi.org/10.7759/cureus.99664.
Gorgas, Evan, and Shawn Dowling. "Bezoar-Induced Small Bowel Obstruction: A Rare Cause of a Common Problem." Journal of Surgical Case Reports 2023, no. 10 (2023): rjad553. https://doi.org/10.1093/jscr/rjad553.