Until recently, medical scientists believed that ulcer was solely caused by an overproduction of digestive fluids at the level of the stomach. Considering that stomach and duodenal ulcers occurred as a consequence of excessive acidity, doctors commonly prescribed antacids as a main form of treatment for gastric disorders. However, these medications alone were unable to completely overcome ulcer and medical scientists had to come up with more reliable drugs. In their attempt to find a better cure for ulcer, scientists have revealed new aspects of the disorder, findings that suggested the involvement of various other factors in the occurrence of digestive disorders. In the 80’s, the findings of Robin Warren and Barry Marshall revealed that ulcer was in fact caused by infection with bacteria. At that time, the discovery came as a great surprise for medical science, and most physicians denied the implication of bacteria in the occurrence and development of ulcer. Scientists believed that bacteria couldn’t populate the interior of the stomach, as it was a very acidic and hostile environment, inappropriate for the proliferation of infectious microorganisms. However, the research conducted by Australian scientists Robin Warren and Barry Marshall suggested the fact that bacteria had a major contribution in the development of digestive disorders such as ulcer. In spite of their efforts to prove the major implication of Helicobacter pylori bacteria in the occurrence of ulcer, the hypotheses sustained by Robin Warren and Barry Marshall were considered to be unfunded and medical gastroenterologists refused to assimilate the ideas presented by the two Australian scientists. After conducting various experiments regarding the involvement of Helicobacter pylori bacteria in the progression of ulcer, Robin Warren and Barry Marshall were finally able to confirm their initial statements. The two scientists proved that people affected by ulcer could be effectively cured with the means of antibiotic medications. Patients who were administered a course of amoxicillin along with the usual treatment with antacids experienced a rapid amelioration of their symptoms and they were less likely to suffer a relapse. Nowadays, it is known for a fact that Helicobacter pylori bacteria are the leading cause of ulcer. The bacteria are responsible for causing both duodenal and stomach ulcers by interfering with the normal activity of the gastrointestinal system. Helicobacter pylori bacteria affect the internal activity of the body on two levels: they weaken the mucosal protective cover of the internal organs and they stimulate an overproduction of digestive fluids. In present, most medical treatments for ulcer include both antacids and antibiotics. By corroborating these two types of medications in the treatment for ulcer, patients can recover rapidly and the chances of relapse are minimal.