The clear liquid coming out of the anus is clinically called mucus, which is mainly mucus secreted by the mucosa of the rectum and colon. Generally speaking, it is mainly due to inflammatory diseases or neoplastic diseases in the rectum and colon, and further colonoscopy is usually required to make a clear diagnosis. Common benign diseases of the colon and rectum mainly include hemorrhoids and colitis, which are usually treated conservatively, with a diet that focuses on avoiding overly greasy, spicy, and irritating foods, as well as good habits of regular daily bowel movements. Patients with hemorrhoids can use various topical hemorrhoid creams and hemorrhoid suppositories, while colitis requires regulation of intestinal flora and even anti-infection treatment to obtain clinical symptom relief. For neoplastic diseases, if they are benign tumors, including villous tubular adenomas, colon polyps, and rectal polyps, they need to be removed endoscopically in a timely manner to obtain clinical symptom relief, and further pathological examination is needed to rule out the possibility of malignancy. Malignant diseases of colon and rectum, especially colon cancer and rectal cancer, require further abdominopelvic CT, especially enhanced CT. when distant metastases are excluded, timely radical resection is usually required, combined with postoperative comprehensive treatment, so as to improve the cure rate.