Case Study: A patient asked, “Doctor, why do I still have appendicitis even though my appendix has been removed?” when we met. I took the ultrasound report and asked about the medical history. It turned out that the patient had undergone appendectomy at a local hospital three years ago because of appendicitis. So I went to the hospital and asked for an ultrasound of the appendix. The ultrasound report said that a 3cm strip was visible in the right lower abdomen and suspected appendiceal stump infection. I asked the patient in detail about the characteristics of abdominal pain, accompanying symptoms and stool, and then carefully performed an abdominal examination and told him that it might not be as simple as “appendicitis”, and then ordered him to undergo a colonoscopy, which confirmed my fears – cloaked in “appendicitis”. The results confirmed my fears – colon cancer in the guise of “appendicitis”! As the economy and living standards continue to improve, the high-fat, high-protein Western lifestyle is becoming more and more popular, and the incidence of colorectal cancer is also increasing in China, becoming one of the most common diseases today, and every year, about 1.2 million patients worldwide are diagnosed with colorectal cancer, and many patients are already in the middle and late stages when diagnosed, which is very regrettable! So how to detect colorectal cancer as early as possible, so that it will not come to do harm in the guise of appendicitis, chronic enteritis, indigestion, hemorrhoids, etc.? Firstly, if you have the following symptoms, you need to go to hospital for colorectal examination as soon as possible: (1) stool with blood or pus and more mucus; (2) change in bowel habit or irregularity, deformation of stool; (3) frequent abdominal pain or distension and flatulence; (4) chronic diarrhea or frequent constipation or alternating diarrhea and constipation; (5) palpable lump in the abdomen or swelling in the anus; (6) unexplained (6) unexplained anemia, wasting and weakness. In the clinic, you can often encounter such patients, after the above symptoms have been dragging not to seek medical attention, or haphazardly take some stool medicine to eat a little, the results until the symptoms are very serious, after six months or even a year or two to seek medical attention, and this time the disease has reached a very serious point, therefore, the patient’s own heart should have a string. Second: Screening Most colorectal cancers develop slowly, and early detection also allows the disease to reach the point of surgical eradication. Studies have shown that annual screening with fecal occult blood can reduce the mortality rate of colorectal cancer by 16%. Current national and international guidelines recommend that colorectal cancer screening begin at age 50 with annual or biennial screening for fecal occult blood and sigmoidoscopy every five years (or fiberoptic colonoscopy every 10 years). Patients with positive fecal occult blood must undergo colonoscopy. Adenomas, serrated adenomas, large hyperplastic polyps (greater than 1 cm), mixed polyps, and hyperplastic polyps located in the proximal colon must be surgically removed if found by colonoscopy. If there are additional risk factors, such as a first-degree relative diagnosed with colorectal cancer, screening needs to start earlier (e.g., beginning at age 40 or 10 years earlier at the age of onset of the youngest immediate family member). For high-risk families (with a history of familial adenomatous polyposis, hereditary nonpolyp colon cancer, or inflammatory bowel disease), the guidelines recommend a more specialized and rigorous prevention program for them in early life.