Recently, we have encountered three cases of patients who did not seek medical attention in time because of diarrhea, resulting in delayed surgery due to metastatic colon cancer. Here, we suggest that patients should be alert to the following conditions and seek medical treatment in time: 1. pain around the anus when diarrhea is present, and falling; 2. stool with mucus or blood, especially with bloody stool, whether fresh blood, dark red blood stool should seek medical treatment in time, never suspicious for hemorrhoids delay, the most easy to relax is intermittent bloody stool, out of stop, mistaken for hemorrhoid bleeding. Regardless of the age of the patient, as long as the blood in the stool, you should seek medical attention. The first hospital of Zhengzhou University, Department of Gastroenterology, Li Jichang 3, diarrhea accompanied by weight loss, loss of appetite and other digestive symptoms; 4, diarrhea accompanied by anemia, pale, weak, etc.; 5, diarrhea at the same time, feel uncomfortable, such as pain in the liver area, cough, fever, etc.; 6, diarrhea after a week of treatment does not relieve; 7, older people, no long-term history of diarrhea in the past, this is the first diagnosis of patients; finally stressed: most patients are not examined in time, but first take some Chinese medicine, or purchase their own medicine, which may start to be effective, but soon relapse, so they go back and forth to this process for a long time, resulting in delaying the disease. Fear of doing colonoscopy, mistakenly recognized the pain is unbearable, and repeatedly delayed backward, take some medicine to see then, so more than six months can not be clearly diagnosed in a timely manner, delaying treatment. Painless colonoscopy can make you painless, pain-free, in an unaware environment to get a satisfactory diagnosis.