If rectal cancer patients have abdominal pain, it should be small abdominal pain, mainly below the navel, and there may be pain in the left lower abdomen, the reason is mainly caused by the rectal tumor itself, if the rectal tumor is larger, there may be hidden pain in the lower abdomen, also sometimes the nature of pain will increase. If the tumor further increases, causing the rectum to be compressed to form intestinal obstruction, there will be no anal exhaustion and defecation, and there will be intestinal flatulence and paroxysmal abdominal pain. The pain will last for a period of time and may be relieved on its own when the patient has exhausted or after a period of time. Therefore, if the diagnosis of rectal cancer is clear, the patient should go to hospital for examination and treatment as much as possible.