成人消化道總長9米多，直腸很短，上接結腸，如果在直結交接部，也可能見鮮血，而鮮血與陳舊血肉眼所見，常模糊。

來源: 大江川於 2015-11-18 14:53:56 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.