This study is a randomized controlled trial that explores how a specific acupuncture treatment might help people with functional constipation. The investigators are testing the idea that a treatment called "acupuncture at the Baliao acupoints" could work by changing the way certain parts of the brain connect and function. These brain changes might help improve gut function and relieve constipation symptoms.

The investigators will work with people who have functional constipation. Some participants will receive the real Baliao acupoint thread embedding, while others will get a sham acupuncture as a comparison. Using special brain imaging techniques, the investigators will look at how the brain's connections and structures change. The investigators will also track how often participants have bowel movements, the consistency of their stools, and their overall symptoms and quality of life. By comparing these results, the investigators hope to understand how the Baliao acupoint treatment works and why it might be effective for constipation.

Inclusion Criteria:

• Age:18 years or older.
• Diagnosed with functional constipation according to the Rome IV criteria.
• The participant has not received any treatment for functional constipation in the past two weeks (except for emergency interventions).
• Right-handed.
• Signed a written informed consent form to participate in this study.

Exclusion Criteria:

• Presence of organic constipation, drug-induced constipation, or systemic constipation.
• Presence of metallic foreign bodies in the body, pacemakers, or other contraindications for MRI examination.
• Communication disorders or unwillingness to cooperate with treatment.

Individual Participant Data contains highly sensitive and personal information about study participants. Sharing IPD could potentially compromise participant privacy and confidentiality.