Colorectal cancer is a relatively typical disease of affluence, which is closely related to our living conditions and dietary patterns. Colorectal cancer in young people is mainly influenced by genetic factors, followed by environmental factors. People with familial colonic polyadenomatosis, colon polyps, soft tissue tumors and bone tumors are at high risk of colorectal cancer. People who often eat high-fat and high-heat food, have irregular life, smoke and drink, and stay up late are much more likely to have colorectal cancer. The most common clinical symptoms of rectal cancer Intestinal obstruction symptoms: mostly occur in the late stage of rectal cancer, which is caused by cancer blocking the intestinal cavity. It often appears as low-level incomplete obstruction first, which is manifested as abdominal distension and constipation, abdominal distension and pain or paroxysmal colic, and when it develops into complete intestinal obstruction, the symptoms intensify. In contrast, left-sided colorectal cancer can sometimes have acute complete colorectal obstruction as the first symptom. Abdominal lumps: rectal cancer lumps are hard, of different sizes, with nodular surface, which can be pushed and fixed in the later stage, and can have pressure pain when combined with secondary infection. The masses of cecum, ascending colon and colon cancer are located in the lower right, middle right and upper right abdomen respectively. Abdominal masses suggest larger polyp type cancer or metastasis to surrounding organs. Systemic manifestations: there may be systemic manifestations such as anemia, emaciation, weakness and low fever, which are caused by cancer consumption, blood loss due to cancer ulceration, as well as infection and toxin absorption. At the late stage of rectal cancer, cachexia and corresponding symptoms due to local or systemic metastasis of intestinal cancer may appear. Usually, left-sided colorectal cancer is obvious by symptoms of intestinal obstruction, constipation, diarrhea, bloody stool and mucus-blood stool, while right-sided colorectal cancer is obvious by full negative swallowing symptoms such as anemia and emaciation, as well as abdominal masses. What symptoms should young people be alert to colorectal cancer? 1. Change in stool habit Regularly shaped stool is a manifestation of one’s intestinal health. Sudden thinning of stool, grooves in stool and mucus are all signs of abnormal intestinal tract. 2, repeated blood in the stool Young people with irregular diets and habits can also have blood in the stool, and most of them will diagnose themselves as hemorrhoids and are too shy to go to the hospital. If there is still bleeding after a week of medication, or if the symptoms recur after the medication gets better, you must go to the hospital in time. Abdominal pain is often easy to be ignored by young people, most of them will choose to wait for its own relief, only when the abdominal pain and bloating is very serious, then they will go to the hospital, at this time, mostly accompanied by intestinal obstruction, the condition has been delayed. Therefore, if you have recurrent abdominal pain and bloating for a long time, especially if you feel a lump in the right lower abdomen or left lower abdomen, you must go to the hospital for examination. 3, constipation and diarrhea Most young people have experienced constipation and diarrhea in their lives. If it lasts for a long time and the treatment is not effective after medication, further examination is needed to exclude the possibility of stomach and intestinal tumors.