Efficacy of different dietary fibers for chronic idiopathic constipation: a systematic review and network meta-analysis

Abstract

This study aims to compare the efficacy and safety of different dietary fiber subtypes in treating patients with chronic idiopathic constipation (CIC) through network meta-analysis (NMA). PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to October 23, 2025. The risk of bias was evaluated using the Cochrane RoB 2.0 tool, and treatment rankings were calculated using the surface under the cumulative ranking curve (SUCRA). 17 randomized controlled trials (RCTs) involving 1423 adults with CIC were included. NMA suggested that viscous soluble fibers were associated with greater efficacy compared with placebo in relieving defecation difficulty (high certainty, class 1), and were also associated with improvements in stool consistency and stool frequency relative to placebo (moderate certainty, class 1). According to SUCRA rankings, viscous soluble fibers tended to have a higher probability of favorable performance compared with other dietary fiber subtypes in improving straining during defecation (moderate certainty), stool frequency (low certainty), and stool consistency (low certainty), and was associated with a relatively favorable tolerability profile (moderate certainty). Insoluble dietary fibers showed the highest ranking probability for improvement in overall constipation symptom scores; however, this finding was supported by very low certainty evidence. Overall, the findings suggest that viscous soluble fibers have a higher probability of improving stool consistency, stool frequency, and straining during defecation. In contrast, insoluble fibers showed a relatively higher ranking for improvement in overall constipation symptom scores. These results support a symptom-oriented and individualized approach to dietary fiber selection in the management of CIC.