ABSTRACT
Objective
Given the paucity of prospective randomized evidence on chewing gum for postoperative bowel recovery in elderly spinal fusion patients, this study aimed to assess the efficacy of chewing gum in improving bowel function recovery in the elderly after posterior lumbar fusion surgery.
Methods
This study enrolled 119 elderly patients following posterior spinal fusion surgery between September 2023 and May 2025, and they were randomly assigned to either group 1 (chewing gum) or group 2 (control). The time for the first fluid intake, first oral intake, first sitting up, first bowel sounds, first flatus, and first defecation was recorded as outcome measures. Besides, the anesthesia usage controlled by patients after surgery, abdominal pain, distension, surgical wound pain, nausea, and abdominal girth were assessed and recorded at 24, 48, 72 h after surgery. Statistical analyses were performed using independent t‐test, Mann–Whitney U test, Chi‐square test, or Fisher's exact test, as appropriate.
Result
There are no significant differences observed between the chewing gum and control groups in patient‐controlled anesthesia usage, abdominal pain scores, distension scores, surgical wound pain scores, nausea scores, or abdominal girth (p > 0.05). Similarly, postoperative recovery parameters, including time to first fluid intake, oral intake, sitting up, first bowel sounds, first flatus, and first defecation, showed no statistically significant differences (p > 0.05).
Conclusion
In this single‐center randomized controlled trial, chewing gum did not show a statistically significant effect on early postoperative bowel function recovery in elderly patients undergoing posterior lumbar fusion surgery.
Keywords: bowel function, chewing gum, elderly, spinal surgery
Chewing gum did not improve early bowel recovery after lumbar fusion.
1. Introduction
Postoperative paralytic ileus (POI) refers to a transient impairment of gastrointestinal motility following surgery, clinically manifested by abdominal pain/distension, belching, nausea, vomiting, and constipation [1]. This condition can exacerbate postoperative pain, prolong patient discomfort, delay enteral nutrition initiation, impair wound healing, hinder mobilization, escalate healthcare costs, and dissatisfaction with surgical care [2]. Although POI is most commonly associated with abdominal procedures, it is increasingly recognized in orthopedic surgeries [3]. Following lumbar spinal surgery, POI incidence ranges from 2.6% to 12%, with variability depending on surgical invasiveness and approach [4]. The growing elderly population in China has led to increased rates of lumbar spinal surgery [5]. Since older individuals more commonly suffer from chronic constipation, they are particularly vulnerable to developing POI after spine surgery when compared to younger individuals [6, 7]. The mechanisms underlying ileus following spinal surgery remain poorly elucidated. One proposed hypothesis suggests that intraoperative irritation of the posterior peritoneal innervation may disrupt bowel function. Additionally, several perioperative factors, including pain‐induced sympathetic activation and opioid administration, are thought to contribute to delayed gastrointestinal recovery [8, 9, 10]. Chewing gum, a form of sham feeding, has demonstrated potential to enhance gastrointestinal motility by stimulating the cephalic‐vagal reflex pathway and promoting the release of digestive hormones. While chewing gum has demonstrated potential to enhance postoperative bowel function recovery in various surgical specialties, its application in spinal surgery remains poorly studied. There is one retrospective cohort study that has shown that chewing gum following spinal surgery can accelerate bowel function recovery in the elderly [3]. However, there were several randomized controlled trials that reported contradictory findings after spinal surgery for adolescent idiopathic scoliosis; two trials observed no significant improvement in bowel function recovery, while one trial observed improvement [10, 11, 12]. Besides, there are no randomized controlled studies on whether chewing gum after spinal surgery in the elderly helps promote bowel function recovery. AS a result, the therapeutic benefits of chewing gum remain inconclusive.
Therefore, we conducted this randomized controlled trial with the following specific objectives: (I) To evaluate whether chewing gum significantly accelerates early postoperative bowel function recovery in elderly patients undergoing posterior lumbar fusion surgery, including primary outcomes (time to first flatus, first defecation, first bowel sounds, first fluid/oral intake, and first sitting up) and secondary outcomes (postoperative opioid consumption, abdominal pain/distension/nausea scores, abdominal girth, length of hospital stay, hospitalization expenses, and complication rates). (II) To provide the first prospective, single‐blind, randomized controlled evidence on this topic specifically in elderly spinal fusion patients, thereby filling the current gap in the literature. The strengths of this study include its prospective randomized design, standardized protocols, and focus on an elderly population at higher risk of postoperative ileus. Future multicenter trials are warranted to determine whether chewing gum confers smaller but clinically meaningful benefits in this vulnerable population.
2. Materials and Methods
2.1. Study Design
We enrolled consecutive elderly patients scheduled for posterior spinal fusion surgery between September 2023 and May 2025. The study protocol has received ethical approval from the Ethics Committee. Before participation, written informed consent was obtained from all patients and their legal guardians.
Following enrollment, patients were randomly assigned 1:1 to either the chewing gum group or control group using an online randomization program (www.random.org).
The inclusion criteria are that patients aged > 60 years, who underwent posterior lumbar fusion surgery for degenerative lumbar diseases, such as lumbar disc herniation (LDH), lumbar spinal stenosis (LSS) or lumbar spondylolisthesis (LS), based on clinical symptoms, such as low back pain, lower limb pain and numbness, and radiological imaging, and conservative therapy for at least 3 months without improvement. Exclusion criteria comprised: (1) Prior spinal/abdominal surgery; (2) cognitive/cooperative impairment, such as neuropsychiatric disorders and low education; (3) esophageal obstruction risk; (4) spinal fractures, tumors, infections, or deformities; and (5) poorly controlled diabetes, gastrointestinal disorders, or severe cerebrovascular disease.
The intervention group chewed sugarless gum for 20–30 min four times daily (8:00, 12:00, 16:00, 20:00) from postoperative day (POD) 1 to the first flatus, and three times daily (8:00, 14:00, 20:00) from the first flatus to first defecation, with investigators blinded to group allocation. Besides, the group assignment was also blinded to the person handling the experimental results. Operative parameters, including surgical duration, estimated blood loss, and number of fused segments were recorded. Postoperative assessments included patient‐controlled analgesia (PCA) opioid consumption, abdominal pain scores, distension scores, surgical wound pain scores, and nausea scores (recording from 0 to 10, where 0 indicated no symptom and 10 indicated the worst imaginable symptom) evaluated at standardized intervals on PODs 1–3. Besides, patients' abdominal girth was also recorded on the day before surgery and at the same time on PODs 1, 2, 3. What's more, the time for the first fluid intake, first oral intake, first sitting up, first bowel sounds, first flatus, and first defecation were also recorded. Patients were instructed preoperatively to report these events immediately to the ward nurses. Bowel sounds were assessed by trained nurses or investigators using a stethoscope over the right lower abdominal quadrant. Auscultation was first performed at 6 h after surgery and was repeated every 6 h until bowel sounds were detected. Each auscultation lasted for 1 min, and the assessment was repeated twice at each time point. Nurses also actively asked patients about flatus and defecation at least three times daily during routine ward rounds. Telephone follow‐up was performed only for patients who had not defecated before discharge, with the purpose of recording the exact time to first postoperative defecation. Length of hospital stay, hospital costs, and postoperative complications, classified with the Clavien‐Dindo grading method, including esophageal obstruction, urinary retention, lung infection, incision infection, retroperitoneal hematoma formation, water electrolyte imbalance, acid–base imbalance, hypoproteinemia, hemorrhagic anemia, and cerebrospinal fluid leakage, were also recorded. Primary endpoints included time to flatus, defecation, and hospital stay duration. Secondary endpoints comprised opioid consumption, complication rates, and symptom scores. Adherence was monitored daily via patient diaries and nurse verification. Compliance was defined as completing ≥ 80% of scheduled gum‐chewing sessions.
2.2. Anesthesia Protocol
A standardized anesthesia protocol was implemented for all patients. Anesthesia was induced using target‐controlled infusion (TCI) of propofol (Marsh model, 4 μg/mL) and remifentanil (Minto model, 5 ng/mL) combined with rocuronium bromide (1 mg/kg) to facilitate endotracheal intubation.
Anesthesia was maintained with TCI propofol (4–6 μg/mL) and remifentanil (4–8 ng/mL) titrated to maintain Bispectral Index values between 40 and 60 during surgery. Additional doses of rocuronium were administered as needed to maintain muscle relaxation throughout the procedure. Hemodynamic management included maintaining mean arterial pressure above 60 mmHg.
2.3. Surgical Protocol
All surgical procedures were performed by experienced spinal surgeons following a standardized protocol. With the patient in the prone position under general anesthesia, a midline skin incision was first made to expose the posterior spinal elements, including spinous processes, laminae, facet joints, and transverse processes at the affected levels. Pedicle screw placement was then performed under C‐arm fluoroscopic guidance. Subsequent decompression involved either total laminectomy or hemilaminectomy to adequately relieve neural compression of the nerve roots and spinal canal. Following discectomy, an interbody cage filled with autologous bone graft was carefully implanted to achieve interbody fusion. Finally, the surgical field was thoroughly irrigated with normal saline, a drainage tube was placed, and the wound was closed in layers. This systematic approach ensured consistent surgical technique across all cases.
2.4. Statistical Analyses
Statistical analysis was conducted using SPSS version 25.0 (IBM Corp, Armonk, NY). Continuous variables were expressed as mean ± standard deviation (SD), while categorical variables were presented as frequencies. Normality of continuous variables was assessed using Shapiro–Wilk tests (alpha = 0.05). Comparative analyses were performed using χ2 tests or Fisher's exact tests for categorical data, and Student's t‐tests or Mann–Whitney U tests for continuous variables, depending on data distribution and sample characteristics. A two‐tailed p‐value < 0.05 was considered statistically significant for all analyses. Based on a pilot study, we assumed a minimal clinically important difference (MCID) of 10 h for time to first flatus, with a standard deviation of 15 h [3]. With an alpha level of 0.05 and power of 80%, a sample size of 58 per group was required.
3. Results
3.1. Baseline Characteristics and Operative Parameters
The CONSORT flow diagram for the study is shown in Figure 1. This study ultimately included 119 patients, including 60 in the chewing gum group and 59 in the control group. As detailed in Table 1, the two groups demonstrated comparable baseline characteristics, showing no statistically significant differences in age, gender, body mass index (BMI), diagnoses, comorbid conditions, or prevalence of severe constipation, as shown in Table 1. There were 37 females and 23 males in the chewing gum group, and 30 females and 29 males in the control group. The mean age for the two groups was 67.1 ± 4.9 and 68.4 ± 5.9 years, respectively. In addition, none of the enrolled patients had experienced taking opioids before surgery. Adherence rates were 100% in the gum group, with no significant differences in baseline factors affecting compliance (p > 0.05). No significant difference was found between the two groups in operative duration, estimated blood loss, operative segments, postoperative PCA utilization, length of hospital stay and hospitalization expense, as shown in Table 1. In the two groups, the operative duration was 179.9 ± 62.8 min and 178.1 ± 66.6 min. Although the chewing gum group demonstrated reduced postoperative PCA opioid use, this difference did not reach statistical significance. Both groups demonstrated cumulative dosage, showing a progressive over time. The length of hospital stay in the two groups was 14.0 (12.0, 17.0) and 14.0 (11.0, 18.0) days. Besides, the hospitalization expenses in the two groups were 62018.1 (56824.9, 74945.0) and 67248.0 (57040.0, 81413.1) yuan.
FIGURE 1.
Consort diagram for the study. In this randomized controlled trial of 119 elderly patients undergoing posterior lumbar fusion, postoperative sugar‐free chewing gum did not significantly improve early bowel recovery. These findings do not support routine chewing gum use for bowel recovery in this population.
TABLE 1.
Table demographic and operative data.
| Parameters | Chewing gum group | Control group | p |
|---|---|---|---|
| No. patients | 60 | 59 | |
| Sex | 0.927 | ||
| Female | 37 | 30 | |
| Male | 23 | 29 | |
| Age(years) | 67.1 ± 4.9 | 68.4 ± 5.9 | 0.236 |
| BMI(kg/m2) | 26.2 ± 3.7 | 26.3 ± 3.7 | 0.845 |
| Serious constipation | 0 | 2 | 0.244 |
| Spinal disease (n) | 0.689 | ||
| LDH | 16 | 13 | |
| LSS | 35 | 34 | |
| LS | 9 | 12 | |
| Comorbidities (n) | |||
| Hypertension | 23 | 27 | |
| Diabetes | 0 | 1 | |
| Cardiovascular disease | 7 | 6 | |
| Lung disease | 1 | ||
| Stroke | 1 | 3 | |
| Preoperative opioid medication (n) | 0 | 0 | |
| Operative duration (min) | 179.9 ± 62.8 | 178.1 ± 66.6 | 0.840 |
| Estimated blood loss (ml) | 0.225 | ||
| ≤ 200 | 33 | 42 | |
| 200–400 | 17 | 4 | |
| ≥ 400 | 10 | 13 | |
| Operative segments | 0.378 | ||
| 2 | 21 | 16 | |
| 3 | 25 | 27 | |
| 4 | 12 | 13 | |
| 5 | 2 | 3 | |
| Postoperative PCA (ml) | |||
| 24 h | 48.1 ± 36.5 | 54.1 ± 38.3 | 0.405 |
| 48 h | 95.2 ± 73.1 | 105.0.3 ± 70.1 | 0.409 |
| 72 h | 116.6 ± 98.5 | 141.1 ± 96.7 | 0.200 |
| Length of hospital stay (d) | 14 (12, 17) | 14 (11, 18) | 0.732 |
| Hospitalization expenses (yuan) | 62018.1 (56824.9, 74945.0) | 67248.0 (57040.0, 81413.1) | 0.149 |
Note: Values are expressed as mean ± SD and median (interquartile range).
Abbreviations: BMI: body mass index; LDH: lumbar disc herniation; LS: lumbar spondylolisthesis; LSS: lumbar spinal stenosis.
3.2. Primary Outcomes
The primary endpoint outcomes are presented in Table 2. Patients in the chewing gum group exhibited first flatus at a mean of 28.4 ± 14.3 h compared to 26.8 ± 12.6 h in the control group (p = 0.716). Time to first defecation averaged 109.5 ± 33.0 h in the chewing gum group versus 120.4 ± 46.8 h in the control group (p = 0.299). First fluid intake occurred at 7.6 ± 3.4 h in the chewing gum group and 8.4 ± 4.4 h in the control group (p = 0.337). First oral intake occurred at 16.6 ± 4.4 h in the chewing gum group and 16.6 ± 3.8 h in the control group (p = 0.987).
TABLE 2.
Comparison of postoperative recovery data.
| Clinical outcomes | Chewing gum group | Control group | p |
|---|---|---|---|
| Time to first fluid intake (h) | 7.6 ± 3.4 | 8.4 ± 4.4 | 0.337 |
| Time to first oral intake (h) | 16.6 ± 4.4 | 16.6 ± 3.8 | 0.987 |
| Time to first sit up (h) | 61.3 ± 22.0 | 67.2 ± 30.0 | 0.604 |
| Time to first bowel sounds (h) | 18.3 ± 9.2 | 16.7 ± 7.6 | 0.251 |
| Time to first flatus (h) | 28.4 ± 14.3 | 26.8 ± 12.6 | 0.716 |
| Time to first defecation (h) | 109.5 ± 33.0 | 120.4 ± 46.8 | 0.299 |
First sitting up occurred at 61.3 ± 22.0 h in the chewing gum group and 67.2 ± 30.0 h in the control group (p = 0.604). The time to first bowel sounds was 18.3 ± 9.2 h in the chewing gum group and 16.7 ± 7.6 h in the control group (p = 0.251).
3.3. Secondary Outcomes
As detailed in Table 3, postoperative abdominal pain scores, distension scores, surgical wound pain scores, and nausea scores from POD1‐3 were comparable between groups, and no significant differences were observed. Besides, the abdominal girth was also measured before operation and on POD1‐3, and there were no significant differences found.
TABLE 3.
Comparison of postoperative data.
| Clinical outcomes | Chewing gum group | Control group | p |
|---|---|---|---|
| Postoperative abdominal pain scores (0–10) | |||
| 24 h | 0.4 ± 1.0 | 0.2 ± 0.6 | 0.132 |
| 48 h | 0.3 ± 0.9 | 0.3 ± 0.9 | 0.513 |
| 72 h | 0.2 ± 0.7 | 0.2 ± 0.9 | 0.271 |
| Postoperative distension scores (0–10) | |||
| 24 h | 1.1 ± 2.0 | 0.7 ± 1.2 | 0.345 |
| 48 h | 1.2 ± 1.8 | 0.8 ± 1.4 | 0.202 |
| 72 h | 0.7 ± 1.5 | 0.6 ± 1.1 | 0.515 |
| Postoperative surgical wound pain scores (0–10) | |||
| 24 h | 2.1 ± 1.2 | 2.2 ± 1.3 | 0.721 |
| 48 h | 2.2 ± 1.4 | 2.0 ± 1.3 | 0.413 |
| 72 h | 1.7 ± 1.5 | 1.6 ± 1.2 | 0.938 |
| Postoperative nausea scores (0–10) | |||
| 24 h | 0.3 ± 0.9 | 0.3 ± 0.9 | 0.841 |
| 48 h | 0.5 ± 1.3 | 0.3 ± 1.0 | 0.606 |
| 72 h | 0.4 ± 1.4 | 0.2 ± 0.9 | 0.727 |
| Abdominal girth (cm) | |||
| Preoperation | 94.1 ± 9.1 | 93.7 ± 9.8 | 0.836 |
| 24 h | 95.5 ± 9.1 | 95.0 ± 10.1 | 0.764 |
| 48 h | 95.4 ± 9.3 | 94.7 ± 9.6 | 0.685 |
| 72 h | 95.2 ± 9.3 | 94.6 ± 9.9 | 0.724 |
3.4. Postoperative Complications
In Table 4, during patient stay, the prevalence of complications in the chewing gum group was not significantly different from that of the control group (p = 0.582). The control group showed a higher proportion of patients with at least one Clavien–Dindo grade I complication than the chewing gum group. However, all complications were mild and resolved with conservative management. The most common complications were fluid, electrolyte, and acid–base imbalance, hypoproteinemia, and hemorrhagic anemia. Additionally, one case of postoperative cerebrospinal fluid leakage was observed, which resolved completely with conservative management through bed rest.
TABLE 4.
Comparison of postoperative data.
| Complications (Clavien‐Dindo classification) | Chewing gum group | Control group | p |
|---|---|---|---|
| Esophageal obstruction | 0 | 0 | / |
| Urinary retention | 0 | 1 | 0.492 |
| Pulmonary infection | 0 | 0 | / |
| Incision infection | 0 | 0 | / |
| Retroperitoneal hematoma | 0 | 0 | / |
| Fluid, electrolyte, and acid–base imbalance | 13 | 17 | 0.402 |
| Hypoproteinemia | 9 | 14 | 0.251 |
| Hemorrhagic anemia | 10 | 19 | 0.055 |
| Cerebrospinal fluid leakage | 0 | 1 | 0.492 |
| Patients with at least one Clavien–Dindo grade I complication | 25 | 28 | 0.582 |
4. Discussion
4.1. The Principal Findings
In this single‐center, prospective, randomized, single‐blind controlled trial involving 119 elderly patients undergoing posterior lumbar fusion surgery, chewing gum did not demonstrate a statistically significant effect on early postoperative bowel function recovery. Specifically, there were no significant differences between the chewing gum and control groups in time to first flatus, first defecation, first bowel sounds, first fluid/oral intake, first sitting up, postoperative opioid consumption, abdominal symptom scores, abdominal girth, length of hospital stay, hospitalization expenses, or complication rates. Although the time to first defecation was numerically shorter in the chewing gum group (109.5 ± 33.0 h vs. 120.4 ± 46.8 h), the difference did not reach statistical significance (p = 0.299).
4.2. Effect of Chewing Gum on Postoperative Bowel Function Recovery
POI are prevalent following spine surgery, with a mean incidence of about 9.3%, where vomiting and paralytic ileus constituted the most common manifestations [10, 13]. Compared to young people, elderly patients have a higher risk of gastrointestinal issues following spine surgery, as they usually exhibit greater susceptibility to chronic constipation [6, 7, 14]. Despite being traditionally regarded as a mild adverse event in spinal surgery, POI represents a prevalent cause of prolonged hospitalization, elevated healthcare expenditures, and increased hospital readmission rates [13, 15, 16, 17]. Furthermore, POI may predispose patients to severe complications, including venous thromboembolic events, acute cardiovascular incidents, sepsis, and aspiration pneumonia [17, 18, 19, 20]. As a result, it is imperative to develop effective therapeutic strategies to enhance postoperative bowel function recovery.
Various preventive strategies have been implemented in clinical practice, including early oral feeding protocols, epidural anesthesia techniques, and pharmacologic interventions [21]. Among them, chewing gum has gained widespread attention for its role in preventing POI after surgery due to its convenience and high patient compliance [22]. The efficacy of chewing gum, a form of sham feeding, in enhancing bowel function recovery following various surgical procedures has been demonstrated by multiple clinical studies and meta‐analyses [8, 23, 24]. The proposed mechanisms involve both physiological stimulation of gastrointestinal secretions and neurological activation of vagal pathways. chewing gum elicits cephalic‐vagal reflex activation comparable to actual food consumption, enhancing motility throughout the gastrointestinal tract while minimizing nausea and vomiting risk [22]. The mechanochemical stimulation of mastication elevates plasma concentrations of regulatory peptides, including gastrin, neurotensin, and pancreatic polypeptide, and increases duodenal alkaline secretion, collectively augmenting digestive function [22, 25]. Besides, emerging evidence suggests that xylitol, a common component of sugar‐free gum, may exert mild osmotic effects that could further contribute to intestinal motility enhancement [26].
A retrospective cohort study conducted by Du et al. had reported that chewing gum in elderly patients following spine surgery helped bowel function recovery, with the time for the first flatus and first defecation markedly shortened. However, for AIS patients who also underwent spinal surgery, prospective randomized trials have shown that chewing gum has no significant effect on postoperative bowel function recovery parameters [10, 11]. They concluded that chewing gum may not be imperative for AIS patients [10, 11]. Because evidence from randomized controlled trials in elderly patients undergoing lumbar fusion surgery remains limited, we conducted this trial to evaluate the effect of chewing gum on early postoperative bowel function recovery in this population. In our study, there were no significant differences in postoperative bowel function parameters, including the time for the first fluid intake, first oral intake, first sitting up, first bowel sounds, first flatus, and first defecation. Besides, chewing gum did not show a statistically significant effect on gastrointestinal symptom scores, postoperative PCA consumption, length of hospital stay, or hospitalization expenses in elderly patients undergoing posterior lumbar fusion surgery. Interestingly, the direction of the observed effects was not fully consistent: The chewing gum group had a slightly longer time to first flatus but a shorter time to first defecation. Because neither difference reached statistical significance and the confidence intervals were wide, these findings should be interpreted as random variation rather than evidence of a definite beneficial or harmful effect.
4.3. Strengths, Implications and Future Directions
This study is currently the first prospective, single‐blind, randomized controlled trial to investigate the efficacy of chewing gum in promoting postoperative bowel function recovery following posterior lumbar fusion in elderly patients with lumbar degenerative diseases. The strengths of this study include its prospective randomized design, standardized anesthesia and surgical protocols, rigorous outcome assessment, and blinding of outcome assessors. A distinctive feature is the focus on an elderly population, who are at higher risk of postoperative ileus and chronic constipation. Based on the current findings, there is insufficient evidence to support a clear routine benefit of chewing gum in this specific population. Although our study found no significant increase in complications, potential harms of chewing gum, such as oral mucosal irritation or aspiration risk in elderly patients with reduced gag reflex, warrant consideration. The absence of serious adverse events suggests a favorable safety profile, but clinicians should monitor for individual tolerance. Future studies should include patient‐reported outcomes (e.g., gum acceptability scales) to better quantify risks. While this trial does not support a routine benefit of chewing gum, it highlights the need for larger, multicenter studies to detect smaller but clinically meaningful differences in this vulnerable population, the present study may have been underpowered to detect smaller but potentially clinically meaningful differences.
4.4. Limitations
However, there are several limitations. Firstly, the single‐center design involving a homogeneous population may limit generalizability to diverse ethnic groups or practice settings. Secondly, while patient blinding would have been challenging to implement, the design may have introduced potential selection bias. Thirdly, interobserver variability in bowel sound auscultation among research team members with differing clinical experience may have introduced heterogeneity in data collection. Fourthly, postoperative outcomes were mainly assessed within the early postoperative period. Although telephone follow‐up was used to ascertain the time to first defecation in patients discharged before defecation, longer‐term gastrointestinal symptoms and patient‐reported recovery were not evaluated. Lastly, the sample size calculation was based on the best available evidence at the time, which was a retrospective cohort study in elderly patients undergoing lumbar spinal surgery. Because retrospective data may overestimate treatment effects, the present study may have been underpowered to detect smaller but potentially clinically meaningful differences.
5. Conclusion
This study is currently the only randomized, single‐blind clinical trial to investigate the efficacy of chewing gum in promoting postoperative bowel function recovery following posterior lumbar fusion in elderly patients with lumbar degenerative diseases. No statistically significant effect of chewing gum was observed on early postoperative bowel function recovery in this population. Although the time to first defecation was numerically shorter in the chewing gum group, the difference did not reach statistical significance. Therefore, these findings should be interpreted with caution. Larger, multicenter trials are warranted to determine whether chewing gum may confer smaller but clinically meaningful benefits in this patient population.
Author Contributions
Fuze Liu: conceptualization, investigation, writing – original draft, methodology, validation, formal analysis, writing – review and editing, project administration, data curation. Ying Jiang: project administration, data curation. Hai Wang: project administration, data curation, conceptualization, investigation, funding acquisition, writing – review and editing, visualization, supervision. Meijia Zhang: project administration, data curation. Gaoyang Li: data curation, project administration. Xiaoyan He: project administration, data curation. Qinlu Wang: project administration, data curation. Lin Zhang: project administration, data curation. Yifei Li: conceptualization, investigation, methodology, validation, writing – original draft, data curation. Yaping Chen: project administration, data curation, conceptualization, investigation, funding acquisition, writing – review and editing, visualization, supervision. Tian Liu: project administration, data curation.
Funding
This work was supported by Peking Union Medical College Hospital Talent Cultivation Program (Category C) No. UBJ10025.
Ethics Statement
This study has been agreed to exemption from ethical approval and consent to participate by the Ethics Committee of Peking Union Medical College Hospital (K23C1372) and was registered with the Chinese Clinical Trial Registry (Registration Number: ChiCTR2300072865).
Conflicts of Interest
The authors declare no conflicts of interest.
Contributor Information
Yaping Chen, Email: 18612672357@139.com.
Hai Wang, Email: wanghai907@hotmail.com.
Data Availability Statement
The data that supports the findings of this study are available in the Supporting Information of this article.
References
- 1. Vather R., Trivedi S., and Bissett I., “Defining Postoperative Ileus: Results of a Systematic Review and Global Survey,” Journal of Gastrointestinal Surgery 17 (2013): 962–972, 10.1007/s11605-013-2148-y. [DOI] [PubMed] [Google Scholar]
- 2. Doorly M. G. and Senagore A. J., “Pathogenesis and Clinical and Economic Consequences of Postoperative Ileus,” Surgical Clinics of North America 92 (2012): 259–272, 10.1016/j.suc.2012.01.010. [DOI] [PubMed] [Google Scholar]
- 3. Du X., Ou Y., Jiang G., Luo W., and Jiang D., “Chewing Gum Promotes Bowel Function Recovery in Elderly Patients After Lumbar Spinal Surgery: A Retrospective Single‐Center Cohort Study,” Annals of Palliative Medicine 10 (2021): 1216–1223, 10.21037/apm-20-1077. [DOI] [PubMed] [Google Scholar]
- 4. Fineberg S. J., Nandyala S. V., Kurd M. F., et al., “Incidence and Risk Factors for Postoperative Ileus Following Anterior, Posterior, and Circumferential Lumbar Fusion,” Spine Journal 14 (2014): 1680–1685, 10.1016/j.spinee.2013.10.015. [DOI] [PubMed] [Google Scholar]
- 5. Li Y., Zheng S., Wu Y., et al., “Trends of Surgical Treatment for Spinal Degenerative Disease in China: A Cohort of 37,897 Inpatients From 2003 to 2016,” Clinical Interventions in Aging 14 (2019): 361–366, 10.2147/CIA.S191449. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Vazquez Roque M. and Bouras E. P., “Epidemiology and Management of Chronic Constipation in Elderly Patients,” Clinical Interventions in Aging 10 (2015): 919–930, 10.2147/CIA.S54304. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7. Lee T. H., Lee J. S., Hong S. J., et al., “Risk Factors for Postoperative Ileus Following Orthopedic Surgery: The Role of Chronic Constipation,” Journal of Neurogastroenterology and Motility 21 (2015): 121–125, 10.5056/jnm14077. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Asao T., Kuwano H., Nakamura J., Morinaga N., Hirayama I., and Ide M., “Gum Chewing Enhances Early Recovery From Postoperative Ileus After Laparoscopic Colectomy,” Journal of the American College of Surgeons 195 (2002): 30–32, 10.1016/s1072-7515(02)01179-1. [DOI] [PubMed] [Google Scholar]
- 9. Helman C. A., “Chewing Gum Is as Effective as Food in Stimulating Cephalic Phase Gastric Secretion,” American Journal of Gastroenterology 83 (1988): 640–642. [PubMed] [Google Scholar]
- 10. Meng Y., Lin T., Shao W., et al., “A Prospective Single‐Blind Randomized Controlled Trial of Chewing Gum on Bowel Function Recovery After Posterior Spinal Fusion Surgery for Adolescent Idiopathic Scoliosis,” Clinical Spine Surgery 31 (2018): 132–137, 10.1097/BSD.0000000000000629. [DOI] [PubMed] [Google Scholar]
- 11. Chan C. Y. W., Chiu C. K., Lee C. K., et al., “Usage of Chewing Gum in Posterior Spinal Fusion Surgery for Adolescent Idiopathic Scoliosis: A Randomized Controlled Trial,” Spine (Phila Pa 1976) 42 (2017): 1427–1433, 10.1097/BRS.0000000000002135. [DOI] [PubMed] [Google Scholar]
- 12. Jennings J. K., Doyle J. S., Gilbert S. R., Conklin M. J., and Khoury J. G., “The Use of Chewing Gum Postoperatively in Pediatric Scoliosis Patients Facilitates an Earlier Return to Normal Bowel Function,” Spine Deformity 3 (2015): 263–266, 10.1016/j.jspd.2014.12.001. [DOI] [PubMed] [Google Scholar]
- 13. Hendrickson N. R., Zhang Y., Amoafo L., et al., “Risk Factors for Postoperative Ileus in Patients Undergoing Spine Surgery,” Global Spine Journal 13 (2023): 2176–2181, 10.1177/21925682221075056. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Horowitz J. A., Jain A., Puvanesarajah V., Qureshi R., and Hassanzadeh H., “Risk Factors, Additional Length of Stay, and Cost Associated With Postoperative Ileus Following Anterior Lumbar Interbody Fusion in Elderly Patients,” World Neurosurgery 115 (2018): e185–e189, 10.1016/j.wneu.2018.04.006. [DOI] [PubMed] [Google Scholar]
- 15. Durand W. M., Ruddell J. H., Eltorai A. E. M., DePasse J. M., and Daniels A. H., “Ileus Following Adult Spinal Deformity Surgery,” World Neurosurgery 116 (2018): e806–e813, 10.1016/j.wneu.2018.05.099. [DOI] [PubMed] [Google Scholar]
- 16. Kiely P. D., Mount L. E., Du J. Y., et al., “The Incidence and Risk Factors for Post‐Operative Ileus After Spinal Fusion Surgery: A Multivariate Analysis,” International Orthopaedics 40 (2016): 1067–1074, 10.1007/s00264-016-3148-9. [DOI] [PubMed] [Google Scholar]
- 17. Swong K., Johans S., Molefe A., et al., “Unintended Consequences After Postoperative Ileus in Spinal Fusion Patients,” World Neurosurgery 122 (2019): e512–e515, 10.1016/j.wneu.2018.10.093. [DOI] [PubMed] [Google Scholar]
- 18. Gifford C., Minnema A. J., Baum J., Humeidan M. L., Vazquez D. E., and Farhadi H. F., “Development of a Postoperative Ileus Risk Assessment Scale: Identification of Intraoperative Opioid Exposure as a Significant Predictor After Spinal Surgery,” Journal of Neurosurgery: Spine 31 (2019): 748–755, 10.3171/2019.5.SPINE19365. [DOI] [PubMed] [Google Scholar]
- 19. Kang B.‐U., Choi W.‐C., Lee S.‐H., et al., “An Analysis of General Surgery‐Related Complications in a Series of 412 Minilaparotomic Anterior Lumbosacral Procedures,” Journal of Neurosurgery: Spine 10 (2009): 60–65, 10.3171/2008.10.SPI08215. [DOI] [PubMed] [Google Scholar]
- 20. Al Maaieh M. A., Du J. Y., Aichmair A., et al., “Multivariate Analysis on Risk Factors for Postoperative Ileus After Lateral Lumbar Interbody Fusion,” Spine 39 (2014): 688–694, 10.1097/BRS.0000000000000238. [DOI] [PubMed] [Google Scholar]
- 21. Bragg D., El‐Sharkawy A. M., Psaltis E., Maxwell‐Armstrong C. A., and Lobo D. N., “Postoperative Ileus: Recent Developments in Pathophysiology and Management,” Clinical Nutrition 34 (2015): 367–376, 10.1016/j.clnu.2015.01.016. [DOI] [PubMed] [Google Scholar]
- 22. Iskander O., “An Outline of the Management and Prevention of Postoperative Ileus: A Review,” Medicine (Baltimore) 103 (2024): e38177, 10.1097/MD.0000000000038177. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Quah H. M., Samad A., Neathey A. J., Hay D. J., and Maw A., “Does Gum Chewing Reduce Postoperative Ileus Following Open Colectomy for Left‐Sided Colon and Rectal Cancer? A Prospective Randomized Controlled Trial,” Colorectal Disease 8 (2006): 64–70, 10.1111/j.1463-1318.2005.00884.x. [DOI] [PubMed] [Google Scholar]
- 24. Liao X.‐Q., Li S.‐L., Peng Y.‐C., Chen L.‐W., and Lin Y.‐J., “Effects of Chewing Gum on Gastrointestinal Function in Patients Following Spinal Surgery: A Meta‐Analysis and Systematic Review,” European Spine Journal 31 (2022): 2536–2546, 10.1007/s00586-022-07304-w. [DOI] [PubMed] [Google Scholar]
- 25. Craciunas L., Sajid M. S., and Ahmed A. S., “Chewing Gum in Preventing Postoperative Ileus in Women Undergoing Caesarean Section: A Systematic Review and Meta‐Analysis of Randomised Controlled Trials,” BJOG: An International Journal of Obstetrics and Gynaecology 121 (2014): 793–799, 10.1111/1471-0528.12696. [DOI] [PubMed] [Google Scholar]
- 26. Tandeter H., “Hypothesis: Hexitols in Chewing Gum May Play a Role in Reducing Postoperative Ileus,” Medical Hypotheses 72 (2009): 39–40, 10.1016/j.mehy.2008.06.044. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data that supports the findings of this study are available in the Supporting Information of this article.