Salix Pharmaceuticals, Ltd. engages in acquiring, developing, and commercializing prescription drugs used in the treatment of various gastrointestinal diseases in the United States. Its products include Colazal capsules for the treatment of ulcerative colitis; Xifaxan tablet, which is a gastrointestinal-specific oral antibiotic for the treatment of patients with travelers' diarrhea caused by noninvasive strains of E coli; Visicol and OsmoPrep tablets for cleansing of the colon as a preparation for colonoscopy; MoviPrep, a liquid polyethylene glycol bowel cleansing product; and Azasan, a drug that suppresses immune system responses and is indicated for preventing rejection of kidney transplants and treatment of severe arthritis. The company also offers Anusol-HC and Proctocort, the hydrocortisone creams and suppositories, which are indicated for use in inflamed hemorrhoids and postirradiation proctitis, as well as an adjunct in the treatment of chronic ulcerative colitis and various inflammatory conditions; and Pepcid and Diuril oral suspensions, which are used for gastrointestinal indications that include the treatment of duodenal ulcer, benign gastric ulcer, and gastro esophageal reflux diseases. Salix Pharmaceuticals' products that are under development phase include Granulated Mesalamine that is used as a maintenance treatment for ulcerative colitis using a dosing regimen; Balsalazide Disodium tablets for treatment of acute and active ulcerative colitis; and Sanvar to treat acute esophageal variceal bleeding. The company has collaboration and product acquisition agreements with aaiPharma LLC; Alfa Wassermann S.P.A.; ALW Partnership; Biorex Laboratories Limited; Cedars-Sinai Medical Center; the Debiopharm Group; Dr. Falk Pharma GmbH; King Pharmaceuticals, Inc.; Menarini Pharmaceutical Industries S.R.L; Merck & Co., Inc.; Norgine B.V.; and Shire Pharmaceuticals Group plc. Salix Pharmaceuticals was founded in 1989 and is headquartered in Morrisville, North Carolina.