Blood in the stool without pain and no blood on the tissue may be caused by digestive or systemic diseases. Blood in the stool without pain, no blood on the paper, indicating that the bleeding site is above the anus. 1. Middle and lower gastrointestinal diseases such as colorectal cancer, ischemic bowel disease, ulcerative colitis, other infectious enteritis (commonly caused by bacteria and viruses), radiation enteritis, intestinal diverticulitis, intestinal hookworm, colorectal polyps and intussusception, etc., can cause blood in stool. 2. Upper gastrointestinal diseases such as esophagogastric fundus varices, gastric and duodenal diseases, peptic ulcer, rare causes of gastric smooth muscle tumor, upper gastrointestinal lymphoma, acute gastric dilatation, hemorrhagic gastritis, etc., diseases of the upper gastrointestinal tract adjacent to the organs or tissues, such as biliary tract stones, gallbladder cancer, cholangiocarcinoma, and peripelvic carcinoma and vascular involvement can cause blood in the stool. 3. Systemic diseases such as allergic purpura, hereditary hemorrhagic capillary dilatation disease, others include hemophilia, vitamin C and vitamin K deficiency, severe liver disease, leukemia and sepsis. Patients with blood in the stool have different signs and symptoms due to different etiologies. The patient’s history, physical examination, and imaging studies should be combined to guide the next step in the treatment plan.