内ない肛こう門もん括かつ約やく筋きんMeaningsNoun1. internal anal sphincter (muscle)Kanji used内inside肛anal門gate括tie a loop around約promise筋muscleComposed of内ないwithin ...; inside ...Suffix肛こう門もんanusNoun括かつ約やく筋きんsphincter (muscle); constrictorNoun