Provided herein is a bulk composition comprising the trihydrate form of (3S, 4R, 3′；R)-6-[4-(4-amino-5-chloro-2-methoxy-benzoylamino)-3-methoxy-piperidin-1-yl]-hexanoic acid 1-azabicyclo[2.2.2]oct-3′；-yl ester di-hydrochloride salt. Provided are also pharmaceutical compositions and dosage forms comprising the trihydrate form, and methods and uses for treating a gastrointestinal disorder in a subject with the trihydrate form. In some embodiments, the gastrointestinal disorder is gastroesophageal reflux disease (GERD), dyspepsia (such as functional dyspepsia or functional motility disorder), gastroparesis, paralytic ileus, post-operative ileus, emesis, nausea, heartburn, intestinal pseudo-obstruction, irritable bowel syndrome (IBS), constipation, enteral feeding intolerance (EFI), or esophagitis. In some embodiments, the gastrointestinal disorder is post-operative ileus, chronic grass sickness, constipation, megacolon, gastritis, gastrointestinal stasis, or abomasal emptying defect.
