Method of treating functional bowel disorders

A method of treating at least one symptom of irritable bowel syndrome selected from the group consisting of:

• abnormal stool frequency, abnormal stool form, abnormal stool passage, passage of mucus and feeling of abdominal distension in a subject in need thereof comprising administering to said subject a therapeutically effective amount of a compound of Formula I:
• wherein, R1 and R2 independently represent hydrogen, halogen or a C1-C6 alkyl group;
• or R1 and R2 together with the carbon atom to which they are attached form a cycloalkylene group having 5 to 6 carbon atoms;
• R3 and R4 independently represent hydrogen or a C1-C6 alkyl group;
• R5 is hydrogen, C1-C6 alkyl,
• or —C(O)—NH—R6
• wherein m is an integer from about 1 to about 3, X is halogen and R6 is a C1-C6 alkyl group;
• and
• Ar is a substituted or unsubstituted phenyl, 2-thienyl or 3-thienyl group;
• and
• n is 2 or 3;
• or a pharmaceutically acceptable salt thereof.