This prospective, observational, multi-center study aims to compare the efficacy of elobixibat and prucalopride in increasing complete spontaneous bowel movements (CSBMs) in patients with functional constipation (FC) or irritable bowel syndrome with constipation (IBS-C) over an eight-week treatment period. The study includes adults diagnosed per Rome IV criteria who have failed conventional treatments for at least three months.

The primary outcome is the increase in CSBMs per week over eight weeks. Several secondary outcomes will also be assessed, including stool consistency, time to first CSBM, patient-reported symptom relief, patient satisfaction, rescue medication use, adverse events, and degree of straining during defecation.

Assessments will occur at baseline, four weeks, and eight weeks for stool consistency and symptom relief, while time to first CSBM will be recorded during the first week of treatment. Patient satisfaction will be evaluated at eight weeks, and rescue medication use and adverse events will be monitored throughout the study. The severity of straining during defecation will be assessed at baseline and at eight weeks.

The target sample size consists of 150 participants in India, and the estimated duration of the study is 6 months from the first enrollment to the final analysis. By comparing elobixibat and prucalopride, this study aims to generate real-world evidence on their effectiveness in improving bowel movement frequency, symptom relief, and patient satisfaction while ensuring safety and tolerability.