sigmoidoscopy

例句：

1. 1. He underwent a sigmoidoscopy to rule out any potential colon cancer.
   他接受了一次乙状结肠镜检查，以排除任何潜在的结肠癌。
2. 2. The doctor recommended that she undergo a sigmoidoscopy for her chronic constipation.
   医生建议她接受一次乙状结肠镜检查，因为她有慢性便秘。
3. 3. During the procedure, the doctor carefully examined the sigmoid colon for anyabnormalities.
   在检查过程中，医生仔细检查了乙状结肠，以寻找任何异常情况。