Emily Lyon, a 23-year-old from Cambridge, has experienced severe gastrointestinal distress linked to prolonged use of proton pump inhibitors (PPIs), medications commonly prescribed to treat acid reflux. Lyon’s symptoms, which escalated over the past year, included intense abdominal cramps, bloating, and frequent diarrhoea, resulting in a significant weight loss of three stone within two months. The condition left her too weak to work and forced her to pause her theater studies degree.

Lyon was first prescribed PPIs, specifically omeprazole, at age 17 to manage her chronic heartburn. While the medication has alleviated her reflux symptoms to some extent, she was recently diagnosed with small-intestinal bacterial overgrowth (SIBO). SIBO occurs when abnormally high numbers of bacteria accumulate in the small intestine, an area that typically hosts fewer bacteria than the large intestine, causing symptoms like bloating, excessive flatulence, and diarrhoea.

A recent review of 29 studies published in the Journal of Clinical Medicine found that each additional month on PPI therapy increases the risk of developing SIBO by approximately 4.2%. The reduction of stomach acid caused by PPIs is thought to allow bacteria that would normally be eradicated to survive and proliferate in the small intestine. The risk appears highest among individuals using PPIs for more than six months, leading experts to emphasize the importance of regularly reviewing the necessity of continued PPI treatment.

Despite this, Lyon and many others find it difficult to discontinue PPIs due to the return of severe reflux symptoms, often described as “unbearable” and resembling a “rope burn” in the chest. Lyon’s underlying condition, a hiatal hernia where part of the stomach pushes into the chest cavity, remains untreated surgically, as doctors remain uncertain about the potential benefits of such intervention. This leaves her reliant on PPIs despite the side effects.

PPIs, including omeprazole, lansoprazole, and esomeprazole, represent one of the most widely prescribed medication classes in the UK, with approximately 73 million prescriptions in England during 2022 and 2023. Clinical guidelines recommend treatment durations typically measured in weeks and advise annual reviews for long-term users. However, studies indicate frequent overprescription and prolonged use without appropriate reassessment. Research involving 77,000 patients found only 4% of those on PPIs for over six months had a clear indication for extended therapy, and a quarter of users take the drugs for over a year without review.

Consultant gastroenterologist Professor Peter Whorwell notes that PPIs are often prescribed too broadly, sometimes in response to vague gastrointestinal symptoms rather than confirmed acid-related conditions. Clinical scientist Professor Anthony Hobson points out that PPIs are sometimes used inappropriately, such as for hoarseness, where acid is not the underlying issue.

In addition to increasing the risk of SIBO, long-term PPI use has been associated in some studies with elevated risks of conditions including heart disease, diabetes, and respiratory infections, though causation is not definitively established. These potential risks underscore the need to balance benefits and harms when prescribing PPIs, particularly for extended periods.

Stopping PPIs can lead to “rebound reflux,” a phenomenon where acid production temporarily surges after withdrawal, often prompting patients to resume medication. This occurs due to elevated levels of gastrin, a hormone that stimulates acid secretion during PPI use. Experts recommend tapering doses gradually to mitigate rebound symptoms and suggest lifestyle changes such as elevating the head of the bed, reducing caffeine and alcohol intake, and considering alternatives like H2 blockers or alginates for symptom management.

Lyon has recently completed a course of antibiotics to treat her SIBO but remains wary of discontinuing PPIs due to the severity of her reflux. She hopes to undergo surgery to correct her hernia, which could provide relief and reduce her dependence on acid-suppressing medications. Until then, she faces the challenge of managing the side effects of long-term PPI use while seeking a more definitive solution.