perianal infection

例句：

1. 1. He developed a perianal infection after a trip to the beach.
   他在去海滩旅行后患上了肛门感染。
2. 2.The doctor diagnosed her with a perianal infection and prescribed antibiotics.
   医生诊断出她患有肛门感染，并开了抗生素。
3. 3. The patient was advised to wash his perianal area frequently to prevent infections.
   病人被建议经常清洗他的肛门区域以防止感染。