Compositions for use in the regulation of subnormal pH values in the intestinal tract and for treatment of bowel diseases. The compositions comprise a coating and a substantially insoluble alkaline material confined within said coating, the composition being adapted so as to ensure the availability of an amount of said pH regulating alkaline material in the lumen of the gastrointestinal tract exhibiting subnormal pH values. E.g. in the proximal small intestine, the mid small intestine, the distal small intestine, the caecum, the ascending colon, the transverse colon, the descending colon, the sigmoid colon and/or the rectum. The compositions may also comprise a medicament for treatment of bowel diseases, e.g. 5-aminosalicylic acid for the treatment of Crohn's disease and colitis ulcerosa. The administration may be oral compositions or enemas or suppositories.