With the accelerated pace of modern life and changes in diet and work habits, many office workers encounter a frequent symptom that causes a lot of trouble, that is, blood in the stool. When encountering blood in stool, people often have two possible reactions, either they think it is a small problem and ignore the symptoms, or they suspect it is rectal cancer and are in a state of panic. How should we treat and deal with it? Today, we will discuss this issue in our microscience. Identifying the cause and location of bleeding by color Blood in stool can be described as bright red, dark red or tar-like, i.e. black stool, in terms of color. The color depends on whether the bleeding is in the upper or lower gastrointestinal tract, the size of the bleeding and how long the blood stays in the gastrointestinal tract. Black stools, also known as tarry stools, are the main manifestation of upper GI bleeding, where the blood stays in the GI tract for a long time and the iron in the hemoglobin combines with sulfide to form iron sulfide under the action of intestinal bacteria, thus making the stool appear black. The main causes of upper gastrointestinal bleeding are peptic ulcer and erosive gastritis. When bleeding is heavy and rapid, black stools may also turn into red bloody stools, which may be accompanied by vomiting of blood, requiring vigilance. Bloody stools are mainly blood rapidly expelled through the anus within a short period of time, and the location of the lesion is mostly located at the end of the rectum or the anal opening, including hemorrhoids, anal fissures, rectal prolapse, etc. The swelling can often be touched or accompanied by obvious pain, which is easier to identify. Dark red blood stool or mucus-purulent stool refers to the discharge of blood or mucus mixed with stool, which is commonly seen in colorectal tumors and ulcerative colitis, etc. Jam-like stool can also occur in infants and children with intussusception, while dysentery, amoebic infections and other diseases are often accompanied by pus and blood stool. List of blood in stool symptoms of common diseases Gastric ulcer, erosive gastritis: tarry black stools, rhythmic pain in the upper abdomen, clearly related to eating, heavy drinking, and mental stress. Hemorrhoids: bright red bloody stool predominantly with pus at the moment of infection, attached to the surface of the stool, not significantly mixed with it, no significant pain in internal hemorrhoids, external hemorrhoids can be accompanied by significant pain. Mainly bleeding after stool. Anal fissure: bleeding adheres to the surface of feces or blood stained by hand paper, bright red, and accompanied by severe pain during defecation. Mainly bleeding during defecation. Inflammatory bowel disease: mucus and blood stool, more turbid, mixed in stool, may be accompanied by abdominal pain, fever and other symptoms. Intestinal polyps: painless bloody stools, which may be bright red or dark red, and may be accompanied by changes in bowel habits. Colorectal cancer: mucopurulent stool, bleeding mixed with stool, accompanied by weight loss, abdominal pain, etc. Positive stool occult blood test. Can blood in stool be colorectal cancer? How to check to confirm the diagnosis? Not all blood in stool means intestinal tumor, and not all intestinal tumors may have blood in stool. In particular, early colorectal cancer or right hemicolectomy cancer is often not primarily characterized by blood in the stool. Early stage rectal cancer may only have a change in bowel habit or a small amount of painless bright red blood in stool, and patients often think it is hemorrhoids and ignore the disgusting consultation. When the tumor continues to progress and develops to middle and late stage rectal cancer, typical mucus-purulent blood stool will appear, as well as abdominal pain, weight loss, fever, thin shape of stool, etc. If the tumor blocks the intestine to form obstruction, there will be more intense abdominal pain, abdominal distension and stopping defecation and exhaustion. When tumor is suspected, you should go to hospital in time. The easiest way to detect tumor is anal examination, which is the simplest screening method and can detect more than 70% of rectal tumors. In addition, blood can be drawn for tumor marker examination, including CEA, CA199, etc. When the significant increase exceeds 2-3 times of normal value, colorectal cancer should be highly suspected. The best way to confirm the diagnosis is colonoscopy, which is the “gold standard” of tumor diagnosis, although it is painful, but it can observe the whole colon and rectal intestine under the direct vision of naked eyes, and if abnormalities are found, pathological diagnosis can be taken. What kind of people need to be alert to the risk of colorectal cancer? People with clear family history of colorectal cancer, especially those whose immediate family members have colorectal cancer, will have a greatly increased risk of cancer and must be highly alert. The general population can start to consider routine colonoscopy at the age of 40 or above, while those who have a clear family history and first-degree relatives with colon cancer are advised to advance the examination time and start to receive colonoscopy after the age of 30. It is worth noting that a long-term high-fat, low-fiber diet, red meat intake, and alcohol and tobacco abuse are also major factors in the development of colorectal cancer, while a high-fiber, low-fat diet can significantly reduce the risk of colon cancer. In addition, some diseases such as intestinal polyps, ulcerative colitis and Crohn’s disease can also increase the risk of cancer, especially adenomatous polyps larger than 2 cm in diameter, which should be removed promptly. In conclusion, blood in the stool is a very common symptom and does not require excessive stress. Of course, if blood in the stool exists for a long time, even if it is not a tumor, it should be treated promptly. People with family history of tumor should be highly alert to the risk of colorectal cancer and need regular checkups and timely treatment.