The appearance of dark red mucus blood in the stool, mostly considered bleeding site in the colon, mostly caused by ulcerative proctitis, colon polyps, colon cancer and other diseases. 1. Ulcerative proctitis: In addition to dark red mucus blood in the stool, this disease is often accompanied by malnutrition, weight loss and other systemic symptoms. 2. Colon polyps: polyps are elevated lesions on the intestinal wall. For larger colon polyps, bleeding may occur, and blood mixed with intestinal contents is discharged, so it is often accompanied by mucous dark red bleeding after stool. 3. Colon cancer: Tumor rupture can be accompanied by bleeding, so there is mucus blood in the stool. In addition, colon ascariasis, amoebic dysentery, chronic bacillary dysentery and other diseases, may also appear dark red stool with mucus. Therefore, if you find dark red stools with mucus, you should consult a doctor promptly, complete the examination, make a clear diagnosis, and follow the doctor’s instructions for treatment.