This invention provides novel peptides and methods to prevent, control, and treat an inflammation, cancer and other disorders, particularly of the gastrointestinal tract and the lung by administering at least one agonist of guanalyte cyclase receptor either alone or in combination with a compound selected from i) 5-aminosalicyclic acid (5-ASA) or a derivative or a pharmaceutically acceptable salt thereof; ii) mercaptopurine; or iii) an anti-TNF therapy.