Capecitabine tablets can treat rectal cancer. Capecitabine is a new type of cytotoxic drug of fluorouracil methionine salt. Capecitabine can be metabolized to fluorouracil by thymidine phosphorylase catalytic action in tumor tissues, thus exerting antitumor effects. Capecitabine is a commonly used drug in the treatment of rectal cancer, widely used in adjuvant chemotherapy and palliative chemotherapy for rectal cancer, as one of the drugs of choice for rectal cancer. Studies have shown that the drug significantly prolongs the time to disease progression and overall survival time of patients, and is effective in the maintenance treatment of advanced colorectal cancer in the elderly. Taking capecitabine tablets may cause adverse reactions such as decreased appetite, nausea, vomiting, throat discomfort, headache, and bone marrow suppression. Capecitabine tablets are contraindicated in patients with hypersensitivity, severe renal impairment, and dihydropyrimidine dehydrogenase deficiency. Patients should follow the doctor’s instructions to use the drug, do not use the drug without authorization, if any adverse reaction occurs after taking the drug, should go to the hospital in time.