 The primary objective of the study is to assess whether a 6-week titration compared with a 1-week titration is effective in reducing the incidence of dimethyl fumarate DMF Tecfidera-related gastrointestinal GI adverse events AEs in participants with multiple sclerosis MS. The secondary objective of this study is to assess whether a 6-week titration compared with a 1-week titration is effective in reducing the average severity and duration of GI symptoms over 12 weeks of DMF treatment in this study population. 