There is a paragraph said just prior to the על חטא section of the Yom Kippur service that begins:
אתה חופש כל חדרי בטן
A (fairly) literal translation would be, "You search all the chambers of the stomach"
Since this paragraph introduces the lists of sins and is followed by a request that G-d forgive our sins, I assume that there is some connection between the stomach and sins. Why is that connection? What is G-d "searching" for in these chambers?