A comparative study of fennel and dimethicone capsule effects on flatulence rate after cesarean section: A double-blind randomized controlled trial.

Background: Flatulence is one of the gastrointestinal complaints after a cesarean section (C-section). A host of treatments have been used to reduce this symptom in hospitals, and most of them are based on chemical drugs. It is considered that herbal drugs may have fewer side effects than chemical drugs, and it seems that fennel can reduce flatulence through stimulation of bowel movements. This study compared the efficacy of fennel and dimethicone capsules on the flatulence rate in post-cesarean birth women.

Materials and methods: This study was a parallel double-blind randomized controlled trial, conducted in a teaching hospital. Eligible women who underwent a C-section and had the sensation of flatulence were randomly block allocated to the fennel and dimethicone groups (1:1). Each group received drugs every 6 hours for four doses after restarting oral feeding. Flatulence rate was the main variable measured before and one hour after taking each dose by the visual analog scale (VAS). Data were analyzed by statistical tests including repeated-measures analysis of covariance (ANCOVA) based on the intention-to-treat method in Statistical Package for the Social Sciences (SPSS) version 16.0.

Results: The dimethicone group showed a significant reduction in flatulence (F _(7,245) =198.5, P < 0.001, η² _p = 0.850). The same trend was also obtained for the fennel group (F _(7,266) =215.0, P < 0.001, η² _p = 0.849). However, there was no difference between groups on the flatulence level after adjusting for the baseline level of flatulence (F _(1,72) =0.27, P = 0.607, η² _p = 0.004). The same result was also obtained one hour after taking capsule 4 (F _(1,72) =0.63, P = 0.430, η² _p = 0.009).

Conclusion: Both fennel and dimethicone capsules can reduce flatulence rate after C-section, although there was no significant difference among them.