2, walnut shell boiled water, can treat mouth ulcers. He asked me whether stomach ulcers can be used, I said, walnut shells have a certain astringent effect, so you can try. So, he grabbed a small handful of walnut shells every day, about 50 grams, boiled water, morning and evening each serving. 3 months later, gastric flatulence, gastric ulcers are under control.