The drug being tested in this study is called Vonoprazan (Takecab). Vonoprazan is being tested to treat people who have gastric ulcer, duodenal ulcer, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, idiopathic thrombocytopenic purpura, stomach following endoscopic treatment of early gastric cancer, or H. pylori gastritis. This study will look at the presence or absence of new concerns regarding the safety of triple therapy with Vonoprazan tablets, amoxicillin, and clarithromycin (first-line eradication) and triple therapy with Vonoprazan tablets, amoxicillin, and metronidazole (second-line eradication) for supplemental Helicobacter pylori (H. pylori) eradication in the routine clinical setting. The study will enroll approximately 500 patients.