Evaluation of Fluoxetine for Refractory Constipation With Somatic Symptom Disorder Features

"Participants will receive fluoxetine tablets, 40 mg once daily, administered 30 minutes after breakfast for 12 weeks.~Emergency Rescue Medications: For participants in both groups who cannot have a bowel movement for three consecutive days or have intolerable symptoms, the following rescue medications will be provided:~polyethylene glycol：13.7 g enema Use of rescue medications must be recorded in the bowel movement diary and CRF, including date, time, and dosage. Rescue medications will be provided throughout the study but are not allowed within 48 hours before and after the first treatment. Distributed every two weeks, any bowel movements within 24 hours after rescue medication use will not count as CSBM."

"Participants in the Placebo Control Group will receive placebo tablets that are identical in appearance and taste to the fluoxetine tablets. They will take one placebo tablet orally twice a day for 12 weeks, following the same schedule as the treatment group to maintain blinding.~Emergency Rescue Medications: For participants in both groups who cannot have a bowel movement for three consecutive days or have intolerable symptoms, the following rescue medications will be provided:~polyethylene glycol：13.7 g enema Use of rescue medications must be recorded in the bowel movement diary and CRF, including date, time, and dosage. Rescue medications will be provided throughout the study but are not allowed within 48 hours before and after the first treatment. Distributed every two weeks, any bowel movements within 24 hours after rescue medication use will not count as CSBM."