If black stools occur during the treatment of Helicobacter pylori, it is very likely due to the medication-induced black stools caused by taking potassium citrate bismuth or bismuth pectin. However, to rule out the possibility of upper gastrointestinal bleeding, a fecal occult blood test can be conducted for a clear diagnosis. Treatment of Helicobacter pylori infection requires a two-week quadruple therapy that includes bismuth. At the same time, one should avoid overeating and focus on consuming fresh vegetables and fruits rich in vitamins and easy-to-digest foods. It is also advisable to quit smoking and drinking alcohol, and avoid drinking strong tea, coffee, etc.