The present invention relates to novel crystalline forms of (R)-2-[[[3-methyl-4(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl]sulphinyl]-lH-benzimidazole (Formula 1), to processes for their preparation, to pharmaceutical compositions comprising the same and to the use of such crystalline forms for the treatment of gastrointestinal (GI) disorders.