Anti-constipation composition

A method for relieving or preventing constipation in a human constipated patient or cleansing a bowel of a patient which comprises administering to the patient a therapeutically effective amount of the pharmaceutical composition comprising in an amount sufficient for relieving or preventing constipation in a human constipated patient or cleansing a bowel of a human patient a bi-cyclic compound represented by formula (I):

• where
• V1 and V2 are carbon atoms;
• W1 and W2 are
• R3 and R4 are hydrogen atoms or one of them is OH;
• X1 and X2 are hydrogen, lower alkyl or halogen atom, and at least one of these is a halogen atom;
• Z is a sulfur atom;
• R2 a hydrogen atom or alkyl;
• Y is a saturated or unsaturated C2-10 hydrocarbon chain which is unsubstituted or substituted by oxo, halogen, an alkyl group, hydroxyl or aryl;
• A is —CH2OH, —COCH2OH, —COOH or its functional derivative;
• and
• R1 is a saturated or unsaturated, lower hydrocarbon forming a straight-chain, a branched-chain or a ring, which is unsubstituted or substituted by halogen, oxo, hydroxy, lower alkoxy, lower alkanoyloxy, lower cycloalkyl, lower cycloalkyloxy, aryl, or aryloxy;
• lower cycloalkyl;
• lower cycloalkyloxy;
• aryl or aryloxy,
• a bond between C-13 and C-14 position is a double or single bond, and
• C-15 has a steric configuration of R, S, or a mixture thereof.