rectal sac

例句：

1. 1. The doctor performed a rectal examination to check for any abnormalities.
   医生进行了直肠检查以检查任何异常。
2. 2.During childbirth, the rectal sac can become inflamed and cause pain.
   分娩期间，直肠囊可能会发炎并引起疼痛。
3. 3. The patient was advised to avoid straining during bowel movements, as it could strain the rectal sac.
   患者被建议避免在排便时用力，因为这可能会拉伸直肠囊。