proctodaeum

例句：

1. 1. He was in excruciating pain from his injured leg.
   他的伤腿让他痛苦不堪。
2. 2. The doctor performed a thorough examination of the patient's anus.
   医生对病人的肛门进行了彻底的检查。
3. 3.After eating too much spicy food, he felt his anus itching and uncomfortable.
   吃了太多辛辣的食物后，他感到肛门发痒不适。