Evaluation of Fluoxetine for Refractory Constipation With Somatic Symptom Disorder Features

Summary

The purpose of this randomized, double-blind, placebo-controlled trial is to determine whether fluoxetine is effective and safe for adults with refractory constipation that exhibits Somatic Symptom Disorder (SSD) features-namely, persistent preoccupation with bowel function, heightened perception of defecatory discomfort, and clinically significant somatic symptom burden (PHQ-15 ≥ 10) in the absence of IBS-C abdominal pain criteria. The study will address three primary questions: Efficacy-Bowel Function: • Does 12 weeks of fluoxetine increase Complete Spontaneous Bowel Movements (CSBM) and overall bowel-movement frequency compared with placebo? Efficacy-Somatic Symptom Burden: • Does fluoxetine reduce SSD severity, as measured by the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8)? Safety and Tolerability: • What adverse events occur during fluoxetine treatment, and how do their incidence and intensity compare with placebo?

Timeline

Start

2025-09-01

Primary completion

2026-06-01

Completion

2027-05-30

Drugs

Indications