The study consists of a 1-week, single-blind run-in period and a 4-week, double-blind treatment period. The participants will receive the study drug (TAK-438 placebo tablet) for the 1-week single-blind run-in period. After the run-in period, eligible participants will be randomized into TAK-438 10 mg or placebo treatment groups in a 1:1 ratio. The randomized participants will receive the assigned study drug (TAK-438 10 mg tablet or TAK-438 placebo tablet) for the 4-week double-blind treatment period.