Not all rectal cancers will cause pain. If rectal cancer has not yet caused pain, it means that the rectal tumor is not yet very big and has not yet invaded the surrounding nerves or other organs, otherwise rectal cancer will surely cause pain as well. Also if rectal cancer grows to a certain degree, some abnormal nerves will be produced in the tumor, which will also cause pain. If the tumor is still growing continuously after rectal cancer is treated by radiotherapy and chemotherapy, most patients will have pain after it develops to the advanced stage. At this time, standardized cancer pain treatment is usually needed, which requires gradual escalation of pain medication according to the ladder, and the pain medication should be used on time, and the pain medication should be taken orally as much as possible if it can be taken orally.