The reasons that cause colorectal cancerChronic inflammation of the intestinesCanceration of intestinal adenomaDiet and carcinogens3 ways to examine the colorectal cancer1. Anal finger examination: the simplest is anal finger examination, which is usually used in the diagnosis of rectal cancer, that is, using aseptic gloves to determine whether there is rectal cancer from the anal insertion. 2. Imaging examination: imaging including CT and MRI, through CT and MRI examination, to determine whether there is irregular thickening or enhancement of the intestinal wall, to determine whether there is colorectal cancer. 3. Enteroscopy: enteroscopy is the most intuitive, with enteroscopy, by inserting the location of the focus with enteroscopy, and then biopsy pathology to determine the diagnosis.