The study aims to evaluate the efficacy of a modified Banxia Xiexin Decoction (BXD) for Wei-Pi through a randomized, waitlist controlled trial.

After being informed about the study plan, potential risk and benefits, all subjects will give written informed consent prior to participation and undergo eligibility screening. Eligible participants will be randomized, in a 1:1 ratio, into BXD group and waitlist group.

Inclusion Criteria:

• Permanent resident of Hong Kong with age from 18 to 60
• Have a diagnosis of Wei-Pi (postprandial distress syndrome, ie. at least one of bothersome postprandial fullness (ie, severe enough to impact on usual activities) and bothersome early satiation (ie, severe enough to prevent finishing a regular-size meal) at least three days per week for the last three months, with symptom onset at least six months before diagnosis

Exclusion Criteria:

• Pregnancy or pregnancy planners
• Abnormal liver function (up to twofold the upper normal reference level of ALT)[14] or kidney function (estimated creatinine clearance < 80 mL/min)[15]
• History of diagnosed gastric structural abnormalities through endoscopy /History of gastric removal surgery
• Have G6PD deficiency
• Alcohol or drug abuser
• Taking Chinese medicine within one month
• Unable to read/understand and sign the informed consent document