This is a double-blind, placebo-controlled Phase 2B study to evaluate the efficacy and safety of three different doses (0.5, 1 and 2 mg TID) of Larazotide Acetate as an adjunct to gluten-free diet in the treatment of patients with celiac disease (CD). The diagnosis of CD must have been established by jejunal biopsy as well as serology at some point in time prior to entry into the study. Patients must have symptoms despite being on a gluten-free diet as defined by a celiac disease domain of the gastrointestinal symptoms rating scale equal to or more than 2.0.