What is rectal cancer? Rectal cancer is a malignant tumor between the dentate line of the anal canal and the junction of rectosigmoid colon, which is one of the common gastrointestinal malignancies and accounts for 60% to 70% of the total incidence of colorectal cancer. It accounts for about 60% to 70% of the total incidence of colorectal cancer. Male incidence is more common than female incidence, and most of them occur above the age of 40, and the incidence rate has been increasing and getting younger in recent years. Compared with Westerners, Chinese rectal cancer is generally considered to have the following characteristics: 1. The incidence of rectal cancer is higher than that of colon cancer (rectal cancer and colon cancer refers to the intestinal tube located above the rectum and below the small intestine) are both in the category of colorectal cancer. 2. Low rectal cancer accounts for a high proportion Low rectal cancer refers to rectal cancer within 5 cm of the dentate line of the perineum. The low rectal cancer refers to the rectal cancer within 5cm of the dentate line of the anal canal. The proportion of low rectal cancer among Chinese people is about 70%, and the mass can usually be palpated in rectal finger examination, which is an important reason why we should do rectal finger examination: rectal finger examination can detect most of rectal cancer. Therefore, especially for middle-aged people over 40 years old, you should not be too troublesome and embarrassed not to do rectal finger examination during physical examination; for those who have symptoms such as blood in stool, unformed stool, frequency, irregular stool, etc., they should go to hospital for timely consultation. 3. The proportion of young patients is high. Young rectal cancer patients less than 30 years old account for about 10%-15% of all patients, which is higher than that of other countries. On the whole, the proportion of rectal cancer patients younger than 30 years old is low, but it is easy to miss the diagnosis, and young patients who go to hospital for blood in stool are often misdiagnosed as hemorrhoids by inexperienced doctors. In fact, rectal cancer is often combined with some other manifestations, so that we can distinguish it from other diseases. What are the manifestations of rectal cancer? 1.Symptoms of rectal irritation: frequent bowel movement, change of defecation habit, feeling of falling in the anus before stool, feeling of urgency and heaviness, feeling of incomplete defecation. 2.Symptoms of intestinal stenosis: cancer invasion causes intestinal stenosis. Initially, the stool is deformed and thinned. When partial obstruction of the intestinal canal is caused, there is incomplete intestinal obstruction with abdominal pain, abdominal distension and hyperactive bowel sounds. 3.Symptoms of cancer rupture infection: blood and mucus on the stool surface, or even pus and blood stool. The frequency of symptoms is 80% to 90% for blood in stool, 60% to 70% for frequent stool, 40% for fine stool, 35% for mucus stool, 20% for anal pain, 20% for shortness of breath, and 10% for constipation.