Generally speaking, atrophic gastritis does not cause diarrhea in patients. The main symptoms of atrophic gastritis include dull pain in the upper abdomen, bloating, belching, or accompanied by symptoms such as weight loss and anemia. If a patient with atrophic gastritis experiences diarrhea, they should promptly visit the gastroenterology department or intestinal clinic of a standard hospital to complete routine stool examinations and tests, and if necessary, an endoscopic examination of the colon. In terms of treatment, antidiarrheal medications such as montmorillonite powder can be used, as well as treatments like Bacillus coagulans to regulate the intestinal flora. It is also advised to drink more water to avoid dehydration.