If Barry Marshall had walked into any gastroenterologist's office in 1982 and told them that stomach ulcers could be treated with antibiotics, he would have been shown the door. Not because evidence was lacking. But because the evidence challenged something far more powerful than a scientific theory. It challenged an entire academic, clinical, and pharmaceutical ecosystem built upon a false assumption.
The dogma: stress, acid, and billions of dollars
For most of the 20th century, gastroenterology operated within a simple aetiological model. Gastric and duodenal ulcers were caused by excessive production of hydrochloric acid, exacerbated by psychological stress, smoking, and an inappropriate diet. This model had its roots in the 19th-century physiology of William Beaumont and his experiments with Alexis St. Martin's gastric fistula (1833), and was consolidated by the work of Karl Schwartz in 1910, who formulated the famous dictum: "Ohne Säure kein Ulcus" (no acid, no ulcer).
Over the following decades, this model hardened into an unquestionable medical fact. In the 1950s and 1960s, psychosomatic medicine added a psychological layer: ulcers were the disease of managers, stressed and ambitious people living under pressure. The treatment? A milk diet, antacids, stress reduction, and in severe cases vagotomy (surgical severing of the vagus nerve). Surgeons were operating on ulcers by the thousands every year. Nobody asked why the disease had to be "treated" again every few years.
In the early 1980s, the anti-ulcer drug market was worth billions of dollars. Cimetidine (Tagamet), introduced by SmithKline in 1976, was the first drug in history to exceed one billion