A method is provided for using α2δ subunit calcium channel modulators or other compounds that interact with the α2δ calcium channel subunit in combination with one or, more compounds with smooth muscle modulatory effects to treat functional bowel disorders in patients in need of treatment. According to the present invention, α2δ subunit calcium channel modulators include GABA analogs including gabapentin and pregabalin, fused bicyclic or tricyclic amino acid analogs of gabapentin, and amino acid compounds. Compounds with smooth muscle modulatory effects include antimuscarinics, β3 adrenergic agonists, spasmolytics, neurokinin receptor antagonists, bradykinin receptor antagonists, and nitric oxide donors.