”Hemorrhoids are a very common clinical condition, and blood in the stool is also a common symptom of bowel disease, and is often associated with hemorrhoids. As a result, many patients who have blood in their stool first think they have hemorrhoids; and some less experienced doctors are prone to preconceptions and begin treatment along the lines of “bleeding hemorrhoids”. In fact, hemorrhoids are only one of the diseases that can cause blood in the stool. There are many other clinical diseases that have blood in the stool, such as rectal colon cancer, rectal colon polyps, ulcerative colitis, Crohn’s disease, intestinal tuberculosis, ischemic enteropathy, allergic purpura, antibiotic colitis, and allergic reactions to food and drugs. The first 2 of these diseases are most likely to be masked by the finding of “bleeding hemorrhoids”, which delays the diagnosis and treatment of the original disease. Comments: 1. The incidence of colorectal cancer (rectal and colon cancer) in China has been increasing rapidly over the past 10 to 20 years. 2. The disease is highly prevalent in people aged 41 to 60, followed by middle-aged and young people aged below 40, while patients aged 61 or above rank 3rd. 3.Colorectal cancer can grow in the left or right hemicolectomy, and the symptoms are different: the symptoms of left hemicolectomy appear earlier, such as loose stool, blood in stool, increased number of stools and left lower abdominal pain; the symptoms of right hemicolectomy are more insidious, such as anemia, abdominal pain, constipation, bloating and blood in stool. When the patient has wasting and loss of appetite, most of them are already in advanced stage. 4.Patients with family history of colorectal polyps or cancer should undergo colonoscopy. If the fecal occult blood is positive for many times, you should also be alert to the possibility of colorectal cancer. 5.Once a cancerous lesion of the left half colon is found under colonoscopy, full colonoscopy should still be performed. If the tumor is too large for the mirror to pass through, intraoperative colonoscopy should also be used to see if there is a tumor in the right half of the colon. 6. The fact that “hemorrhoid bleeding” is the first symptom of colorectal cancer and that colonoscopy has not been performed for a long time should be a lesson. Conclusion: When there are tumors and polyps growing in the large intestine, the surface of the tumor is susceptible to inflammatory processes by stool at any time, and the resulting inflammatory exudate can travel down to the anus with stool, which can also cause inflammatory erosion and damage to the surface of the “hemorrhoid nucleus”. Once the feces passes, it is easy to abrade the nucleus and bleeding occurs. Therefore, it is recommended that all patients with blood in the stool should undergo a colonoscopy, and never ignore other diseases of the large intestine because of the cover-up of “bleeding hemorrhoids”.