The present invention relates to a novel crystalline form of 5-methoxy-2-(4-methoxy-3,5-dimethyl-2-pyridinyl)methylsulfinyl-l H-benzimidazole, known under the generic name omeprazole. Further, the present invention also relates to the use of the novel crystalline form of 5-methoxy-2-|(4-methoxy-3,5-dimethyl-2-pyridinyl)methylsulfinyl-lH-benzimidazole for the treatment of gastrointestinal disorders, pharmaceutical compositions containing it as well as processes for the preparation of the novel crystalline form of 5-methoxy-2-(4-methoxy-3,5-dimethyl-2-pyridinyl)methyIsulfinyl-lH-benzimidazole.