From Longman Dictionary of Contemporary Englishbowelsbowels[plural]HBH the system of tubes inside your body where food is made into solid waste material and through which it passes out of your body → intestinemove/empty/open your bowels (=get rid of solid waste from your body) → bowel
Examples from the Corpus
move/empty/open your bowels• You did not move your bowels at 7: 30 as I instructed.• Several days had gone by and I had not moved my bowels. 