The goal of this observational study is to identify the characteristics of brain functional connectivity in refractory constipation and fluoxetine-sensitive patients. The main questions it aims to answer are:
* Investigating the alterations in brain functional connectivity in patients with refractory constipation and fluoxetine-sensitive patients * Assessing the predictive value of brain functional connectivity regarding the efficacy of fluoxetine and standard protocol treatments for constipation.
Participants will receive:
* Standard physiological and psychological assessments of constipation * BOLD-fMRI tests * Standard protocol and fluoxetine treatment
If there is a comparison group: Researchers will compare:
Refractory group/Fluoxetine sensitive group to see the specific brain alterations.
18≤ age ≤ 45 years old
Right-handed
Patients diagnosed as functional constipation according to the Rome IV criteria
Informed consent of patients
Complicated with gastrointestinal organic disease or significant functional abnormalities (tuberculosis, polyps, Crohn's disease, tumors, congenital megacolon, pelvic floor muscle relaxation, abnormal colonic transit test, etc.)
Long-term intense exercise (continuous exercise for more than 8 hours per week, such as marathon runners or triathletes)
No history of chronic pain, no recent major trauma
Drug abuse or tobacco dependence (half a pack or more per day)