The symptoms of reflux esophagitis mainly manifest as chest pain, acid reflux, as well as upper abdominal bloating, belching, nausea and vomiting, etc. Generally, it does not involve the occurrence of mucus in stools. If mucus in stools occurs, we consider two diseases. The first one is chronic colitis, which can cause abdominal pain and diarrhea, and sometimes mucus in stools. The other is ulcerative colitis, whose main symptoms are abdominal pain, diarrhea, and stools with mucus and pus blood. A colonoscopy can be conducted to determine which specific disease is present, and then targeted treatment can be administered based on the results of the colonoscopy.