Colorectal cancer is a malignant tumor of the digestive system, and its occurrence is related to the following factors:

First, dietary factors. A high-fat content and a low fiber content in the diet both lead to an increased incidence of colorectal cancer. Furthermore, long-term consumption of pickled foods can also increase the incidence of colorectal cancer, presumably because these foods contain higher levels of nitrosamine carcinogens.

Second, some benign chronic diseases of the colon, such as adenomatous polyps and certain chronic colitis, can also lead to an increased incidence of colorectal cancer.

Third, environmental factors. Epidemiological studies have found that the occurrence of colorectal cancer is related to geographical distribution. In some environments with a high incidence of colorectal cancer, the content of some trace elements in the soil is too low, leading to a high incidence of colorectal cancer.