This parallel, monocenter, randomised controlled experimental study was carried out at the maternity services of the department of Cerrahpasa Medical Hospital of Istanbul University between January 2018 and April 2018 with the Consolidated Standards of Reporting Trials (CONSORT) guidelines (Fig. 1) [21].

Fig. 1.

Consolidated Standards of Reporting Trials (CONSORT) flow diagram.

Women were randomly assigned to the gum, fennel tea, gum-fennel tea groups and the control group in a 1:1:1:1 ratio. Women in all groups were followed for 48 hours during cesarean delivery.

Inclusion criteria included healthy women who underwent elective cesarean section under general anesthesia, had at least a primary school education, no chronic systemic diseases, no complications during pregnancy (e.g., preeclampsia, gestational diabetes, or placental abnormalities), no history of allergies, a body mass index (BMI) between 18.50 kg/m² and 24.99 kg/m², no prior abdominal surgeries, and no complications during the cesarean procedure. Elective cesarean sections were selected to standardize recovery conditions and reduce variability associated with emergency procedures or complications, such as fetal distress or placenta previa, that might independently affect bowel motility. Women with BMI outside the normal range (18.50–24.99 kg/m²) were excluded to limit variability caused by nutritional and metabolic factors, which could influence intestinal motility.

The exclusion criteria were as follows: age 18 years, multiparous women who had a cesarean section under spinal anesthesia, spontaneous onset of labor, chronic systemic diseases, complications during pregnancy (e.g., preeclampsia, gestational diabetes, or placental abnormalities), a history of allergy, a BMI 18.50 kg/m² or $>$24.99 kg/m², prior abdominal operations, and complications during the cesarean procedure.

Using SPSS 24.0 (IBM Corp., Armonk, NY, USA), a random sequence was generated by an independent researcher who was not involved in recruitment, treatment, follow-up, or data processing, ensuring unbiased allocation. The random sequences were sealed in opaque envelopes to maintain allocation concealment. After obtaining informed consent, nurses opened the envelopes to assign participants into four groups in a 1:1:1:1 ratio. The data analysts were blinded to the group assignments to prevent bias in data interpretation. Although the women, environment, and researchers conducting the interventions were not blinded due to the nature of the applications, strict measures were taken to prevent any communication between subjects and data analysts. This ensured that the analysts could not infer group information from the questionnaire findings, maintaining the integrity of the blind evaluation process.

According to the Obstetrics and Gynecology Hospital protocol, 3000 mL of intravenous fluid was administered during the postoperative period. Oral fluid intake commenced six hours after the cesarean operation performed under general anesthesia, regardless of whether intestinal motility had resumed. Following this, the urethral catheter was removed, and mobilization was initiated. Women who experienced flatulation and defecation were discharged 48 hours after surgery as per hospital protocol. However, those who did not exhibit these outcomes were not eligible for discharge until these criteria were met, ensuring early detection and management of potential complications.

During the follow-up process:

-Bowel sounds of the women were listened to by the researcher using the same stethoscope, which was held over the women’s abdomen following the cesarean section. Bowel sounds were listened to every 15 minutes and the first time the bowel sounds could be heard was determined and recorded by the researcher.

-The time of the first flatulation and the time of the first defecation were determined by verbally asking the women and then recorded by the researcher. The researcher stayed at the hospital until the evaluation of bowel sounds after the cesarean section was completed.

The objective of this study was to evaluate the effects of chewing gum and drinking tea on the postoperative recovery process. Both practices are methods used to encourage bowel movements and facilitate the return of the digestive system to its early functional state. The chewing gum protocol (15 minutes every two hours) was adapted from previous randomized controlled trials demonstrating its efficacy in enhancing bowel motility [22]. Similarly, the fennel tea dosage (2 grams per serving) aligns with traditional practices and studies indicating its antispasmodic effects [15]. The incorporation of these methods within the scope of patient education is intended to reduce postoperative complications by enhancing self-care skills. Four different interventionschewing gum and drinking fennel teawere conducted in this study.

Women in this group chewed sugar-free and non-xylite gum for 15 minutes every two hours (2nd, 4th, and 6th) following the cesarean operation. Therefore, in the current study, women chewed gum for 15 minutes every two hours, following two hours after the cesarean operation. The bowel sounds of the women were listened to and their flatulation times were recorded before and after gum chewing for 15 minutes every two hours. When women were allowed oral intake, gum-chewing activity was terminated completely. Data for the first time of flatulation and the first defecation were collected by verbally asking women, and these data were recorded in the follow-up form.

Women in this group started oral intake 6 hours after cesarean delivery and were allowed to drink 2 grams of fennel tea in the 6th, 8th, and 10th hours (a total of 6 grams of fennel tea). Fennel seeds (2 grams) were put into 150 mL water, boiled at a temperature of 100 °C, and left for 20 minutes. Women were then instructed to drink the tea. Bowel sounds were recorded every 2 hours, before and after drinking the fennel tea. The time of the first flatulation and the first defecation were determined by asking the women themselves and this information was then recorded using the study form.

Women in this group chewed sugar-free and xylitol-free gum for 15 minutes every two hours (2nd, 4th and 6th) following the cesarean section. In accordance with the hospital routine and study protocol, women were started on oral feeding 6 hours after cesarean delivery and were allowed to drink 2 grams of fennel tea (6 grams of fennel tea in total) at 6, 8 and 10 hours.

The women’s bowel sounds were listened to and the duration of flatulence was recorded before and after chewing gum for 15 minutes every two hours. Bowel sounds were recorded every 2 hours, before and after drinking the fennel tea.

Data on the time of first flatulation and first defecation were collected by asking the women verbally and these data were recorded on the follow-up form.

Bowel sounds were monitored at 0, 2, 4, 6, 8, and 10 hours in accordance with the hospital’s routine study protocol. Oral feeding was initiated six hours after cesarean delivery. Data on the time of first flatulation and defecation were collected verbally from the participants and recorded on the follow-up form. Laxative medication was not administered. Participants were not discharged from the hospital until flatulation and defecation were observed. Forty-eight hours post-surgery, bowel sounds were re-evaluated to check for any complications, but none were observed.

In the control group, no placebo or additional intervention was provided. Participants in this group followed the hospital’s standard postoperative care protocol, allowing for a comparison against the intervention groups to evaluate the effects of chewing gum and fennel tea. According to hospital protocol, discharge was contingent upon the occurrence of flatulation and defecation, emphasizing the clinical relevance of these outcomes. This protocol ensures early detection and management of potential complications. Consequently, discharge times were included as a secondary outcome to highlight their significance in postoperative recovery. In addition to monitoring bowel sounds, participants were observed for signs of postoperative complications, including, but not limited to, nausea, vomiting and abdominal pain during their hospital stay.

The main objective of this study was to evaluate the effect of chewing gum and fennel tea on bowel motility after cesarean delivery. The primary outcome directly measures the effect of these treatments. Specifically, it will be assessed by examining factors such as the rate of bowel motility and flatus after cesarean delivery. These measurements are critical to determine the effect of the treatments on bowel function. The researcher assessed bowel sounds at 0, 2, 4 and 6 hours after cesarean delivery.

Secondary outcomes include factors the woman’s first flatulation and the first bowel sounds. These measures will be used to understand the impact of treatments and draw clinically meaningful conclusions more comprehensively. The time of the first flatulation and the first defecation were determined by asking the women themselves and this information was then recorded using the study form.

The study was carried out with four different groups determined by 22 factorial trial levels. The sample size was determined as a total of 120 participants at 80% power and 95% confidence interval in consideration of the meta-analysis conducted on the data of the subjects [23].

Adverse events were defined as any unexpected medical occurrences during or after the interventions, including gastrointestinal discomfort (e.g., bloating, nausea, vomiting), allergic reactions, or surgical site complications requiring medical intervention. Participants were closely monitored for adverse events throughout the 48-hour follow-up period. Any observed events were recorded and reported immediately. No adverse events were identified during the study.

The compatibility of the variables with normal distribution was examined using the Kolmogorov-Smirnov test. For normally distributed (parametric) variables, one-way analysis of variance (ANOVA) was used to compare differences between groups. Categorical data were analyzed using Chi-square and Fisher’s exact tests. The skewness and kurtosis values for these variables were within the acceptable range (–1 to +1), indicating that the data were normally distributed. Therefore, the parametric one-way ANOVA is used to evaluate differences among groups. Statistical analyses were conducted using SPSS Statistics for Windows, Version 24.0 (IBM Corp., Chicago, IL, USA). A p-value 0.05 was considered statistically significant.

The mean age of the subjects was found to be 29.5 $\pm$ 2.77 years, with a mean BMI of 22.75 $\pm$ 1.24 kg/m². The control group included participants aged 35 years and over, while the majority of participants in all groups were between 25 and 34 years. In the chewing gum group, 30% of subjects received secondary school education, 43.4% of those in the fennel tea group were university graduates, 30% of those in the chewing gum and fennel tea group received primary school education, and 40% of the control group received high school education. Smoking status did not differ significantly between the groups (p = 0.405, Table 1) and is not discussed further. All groups underwent a Pfannenstiel skin incision under general anesthesia. The mean duration of the surgical procedure was 40 minutes, with a mean blood loss of 500 mL. Blood loss was estimated visually by the surgical team and documented in milliliters as part of routine clinical monitoring during the procedure. The recorded values for each participant were averaged to calculate the mean blood loss.

It was found that 53.3% of the chewing gum group, 76.7% of the fennel tea group, 76.7% of the chewing gum and fennel tea group, and 83.3% of the control group did not use herbal tea during pregnancy.

Bowel sounds were heard earliest (6.96 $\pm$ 3.41 hours) among the women in the chewing gum and fennel tea group, where all the applications had been performed; bowel sounds were heard latest (20.75 $\pm$ 4.83 hours) among those women in the control group, where no application had been conducted. The bowel sounds of women in the chewing gum and fennel tea group who had been subject to all applications were heard after a minimum of 5.0 and a maximum of 11.2 hours. A statistically significant difference was found between the groups in terms of the times of first hearing bowel sounds. The chewing gum and fennel tea group showed the shortest time to the onset of bowel sounds. This suggests that the control group was more effective than the other groups in accelerating bowel motility (Fig. 2, Table 2).

Fig. 2.

Distribution of the groups according to intestinal motility after cesarean delivery.

The time of the first flatulation was found to be the earliest (15.47 $\pm$ 7.77 hours) among those women in the fennel tea group, with the latest time being found among those (46.55 $\pm$ 14.12 hours) in the control group. Flatulation occurred earlier in the women in the fennel tea group compared with those in other groups. In the fennel tea group, the first flatulation occurred after a minimum of 12.9 and a maximum of 18 hours. A statistically significant difference was found between the groups in terms of the time to first flatulation. The fennel tea group was the most effective in reducing flatulation time, followed by the chewing gum and fennel tea group, the chewing gum group, and finally, the control group, which experienced the longest time to flatulation (Fig. 2, Table 2).

The defecation time after cesarean delivery occurred the earliest (21.02 $\pm$8.75 hours) among those women in the fennel tea group and the latest (57.66 $\pm$ 13.26 hours) among participants in the control group. Among participants in the fennel tea group, intestinal motility occurred after a minimum of 13.2 hours and a maximum of 25.7 hours. A statistically significant difference was found between the groups in terms of the time of first defecation time. The fennel tea group made the defecation time faster than both the chewing gum groups and the chewing gum and fennel tea group. The control group achieved the longest defecation time (Fig. 2, Table 2).

The duration of hospital stay was found to take a long time for participants in the control group, which comprised individuals who experienced no application. While the women in the control group were scheduled for discharge after an average of 52.13 $\pm$ 3.63 hours, the average discharge time was found to be 48.00 $\pm$ 0.00 for those in the other groups (Fig. 2, Table 2).