If a gastric polyp has been removed for half a month, the stomach may become distended, most commonly because the polypectomy wound is not completely healed, and may gradually erode and become severe, leading to localized chronic ulcers, resulting in the appearance of gastric ulcers, which can lead to stomach distention, belching or stomach pain. Alternatively, there may be inflammation in the stomach that causes distention, but usually gastritis is present before the polyps are removed. In either case, the symptoms will slowly improve with the application of gastritis medications or medications to promote gastric motility and to protect the gastric mucosa.