Integrating perspectives on transabdominal intestinal ultrasound in inflammatory bowel disease management: a nationwide cross-sectional survey of physicians and patients in China
Article information
, Zhaojue Wang2,*, Yujun Chen3, Ning Chen4, Yan Chen5, Xiaoqi Zhang6, Xiaoyan Xie3, Ren Mao7, Yue Li,1, Qingli Zhu,2, Minhu Chen7, China IUS GroupAbstract
Background/Aims
The awareness, accessibility, and utilization of transabdominal intestinal ultrasound (IUS) in inflammatory bowel disease (IBD) management from both physicians’ and patients’ perspectives remains unclear in China. This nationwide cross-sectional survey aimed to gauge the current utilization of IUS, physician and patient perceptions and knowledge gap in IBD management across China.
Methods
A structured questionnaire, developed by the China IUS Group, was distributed to 612 physicians (69.8% of gastroenterologists, 28.0% of radiologists) from 38 tertiary hospitals and 1,154 IBD patients.
Results
A total of 91.7% of physicians expressed an intention to incorporate IUS into future clinical practice. However, while 69.3% of physicians reported IUS availability at their institutions, its utilization varied widely. Only 16.5% of physicians applied IUS to more than 75% of their IBD patients. Additionally, 27.1% of physicians reported receiving IUS training. Radiologists were more likely than gastroenterologists to consider IUS as a sensitive tool for evaluating treatment efficacy (48.3% vs. 19.4%, P<0.001), intestinal wall fibrosis (33.7% vs. 27.4%, P<0.001), intestinal fistula (27.9% vs. 11.2%, P<0.001), abdominal abscesses (49.4% vs. 28.6%, P<0.001), and disease severity (30.2% vs. 11.0%, P<0.001). Patients expressed high satisfaction with IUS (76.1%), yet 39.2% had safety concerns.
Conclusions
Despite growing recognition of IUS in China, its wide utilization in IBD management requires further promotion. The notable disparity between gastroenterologists and radiologists regarding IUS underscores the need for targeted, specialty-specific training. Strengthening patient education efforts is essential to further enhance patient acceptance of IUS.
INTRODUCTION
Inflammatory bowel disease (IBD), characterized by recurrent episodes of chronic inflammation in gastrointestinal tract, consists of 2 major forms, ulcerative colitis (UC) and Crohn’s disease (CD). These conditions present a heterogeneous range of symptoms and clinical outcomes that can significantly impair patients’ quality of life [1]. With the rising prevalence of IBD and advancements in therapeutic approaches, there is a growing preference for noninvasive and convenient tools for long-term disease monitoring [2].
Transabdominal intestinal ultrasound (IUS) has emerged as a noninvasive, non-radiative, and cost-effective tool for assessing disease activity, determining disease extent, and predicting outcomes in various intestinal diseases, especially IBD [3]. In China, ultrasound departments often operate independently from radiology departments, with examinations usually conducted and interpreted directly by radiologists specialized in ultrasound and possessing M.D. degrees, rather than technicians or sonographers. Recent studies have provided strong evidence supporting the reliability of IUS in evaluating disease activity and predicting outcomes in IBD [3-10]. It allows real-time, repeated assessments without the need for bowel preparation or contrast agents, making it particularly suitable for monitoring disease progression and therapeutic efficacy over time [4,6,7,11]. Studies have shown that IUS key parameters, especially bowel wall thickness, strongly correlate with endoscopic and histological activity, with high sensitivity and specificity [12]. Compared with computed tomography enterography (CTE) or magnetic resonance enterography (MRE), IUS provides a cost-effective, bedside-friendly modality, especially valuable in resource-limited settings or for patients contraindicated for radiation exposure or sedation [13]. Its utility has extended from initial diagnosis to treatment monitoring and relapse surveillance.
However, the current awareness and utilization of IUS from both physicians’ and patients’ perspectives remains unclear in China. To address this gap, a nationwide survey promoted by the China IUS Group was conducted to gather insights into the current implementation of IUS in IBD management. The findings aim to facilitate its broader adoption and inform the development of clinical guidelines.
METHODS
1. IRB Approval
We conducted this study in compliance with the principles of the Declaration of Helsinki. The study’s protocol was reviewed and approved by the Institutional Review Board of Peking Union Medical College Hospital (IRB No. I-24PJ2495), and the requirement for written informed consent was waived by the IRB.
2. Survey Instruments
The survey was developed using a modified Delphi method [14]: an initial survey administered in Chinese was drafted to assess the awareness, accessibility, and utility of IUS in IBD management, along with its perceived advantages and limitations compared to other diagnostic modalities. Key areas of focus included physician training, clinical application, and barriers to implementation for physicians, as well as patient perspectives on comfort, preferences, and experiences with IUS. A pilot survey was conducted with a cohort of 10 physicians (5 gastroenterologists and 5 radiologists specialized in ultrasound) and twenty patients consulting at Peking Union Medical Hospital. Based on feedback from the initial pilot round, the survey questions were refined and subsequently reviewed by the China IUS Group for further refinement (Round 2) prior to national dissemination. The final version, approved by both groups, was made available online through the Wenjuanxing platform, with the questions included in the Supplementary Materials 1 and 2.
3. Reliability and Validity
Content validity was evaluated by consulting 5 experts in IBD and 7 radiologists specialized in ultrasound during the round 2 pilot survey. These experts assessed the survey items for relevance, essentiality, and clarity [15]. Based on their feedback, 9 items were added, and 4 were removed from the physician survey, while 6 items were added, and 4 were removed from the patient survey. These refinements ensured comprehensive coverage of key themes and that the questionnaire content was adjusted to an appropriate reading and comprehension level for the target population.
Following the second pilot survey, test-retest reliability was assessed by administering the survey to the same group of respondents—10 physicians (5 gastroenterologists and 5 radiologists specialized in ultrasound) and twenty patients—2 weeks apart. The correlation between the 2 sets of responses was calculated using intraclass correlation coefficient (ICC) for ordinal variables (Likert-scale items) and Cohen’s kappa (κ) for categorical variables. The results yielded an ICC value of 0.846 and a κ value of 0.883, indicating a high level of stability. Internal consistency of Likert-scale items was measured using Cronbach’s alpha, which was calculated for each subscale of the survey. The results yielded a Cronbach’s alpha of 0.842 for recognition subscale in physician survey, and a Cronbach’s alpha of 0.849 for recognition subscale in patient survey, demonstrating good internal consistency.
4. Participants
This cross-sectional study was conducted from November 29, 2024, to December 15, 2024. Given that the standard diagnosis and management of IBD in China are currently concentrated in tertiary hospitals, we selected gastroenterologists, radiologists specialized in ultrasound, and IBD patients from 38 hospitals affiliated with members of the IBD Group of the Chinese Society of Gastroenterology as the target population. To maximize survey awareness and participation, members of the IBD Group of the Chinese Society of Gastroenterology were contacted via WeChat and encouraged to distribute the survey to gastroenterologists and radiologists within their hospitals. Assuming a two-sided 95% confidence level (Z=1.96), maximum variability (P=0.5), an acceptable margin of error (d=0.1) and a 25% response rate, each participating unit was requested to obtain at least 10 voluntarily completed surveys from gastroenterologists and 10 from radiologists. Simultaneously, the patient survey was posted on the China Crohn’s and Colitis Foundation (CCCF) Official Account and disseminated to patient groups through IBD group members. Reminders were sent through these channels at the survey’s launch and again 3 days before its closure. Prior to completing the questionnaire, all participants were fully informed, and their informed consent was obtained. The exclusion criteria and process were shown in Fig. 1. Surveys with disproportionately short completion times (<90 seconds) were excluded as invalid responses. Additionally, only the most recent submission from the same IP address was considered in the final survey results. Finally, 612 valid questionnaires were collected from physicians and 1,154 from patients were, yielding an effective rate of 96.8% and 97.5%, respectively.
Inclusion and exclusion process for survey distribution.
5. Statistics Analysis
In this study, statistical analysis was conducted using SPSS 27.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics were presented as frequency (n) and percentage (%). For ordinal variables (Likert-scale responses), the Mann-Whitney U test was used to compare differences between gastroenterologists and ultrasound specialists. For categorical variables, chi-square tests were employed to assess the differences in proportions between gastroenterologists and ultrasound specialists. All statistical tests were two-tailed, and a P-value of less than 0.05 was considered statistically significant.
6. Scoring Rules for Sorting Questions
The WJX system automatically computes the average composite score for sorting question options based on the responses from all participants. This score represents the comprehensive ranking of the options, with a higher score indicating a more favorable ranking. The formula for calculating this score is: option average composite score=(Σfrequency×weight)/number of respondents for the question. The weight assigned to each option depends on its position in the sorting. For instance, if 3 options are included in the sorting, the first position carries a weight of 3, the second position 2, and the third position 1. The score is also contingent upon the number of options available. For example, in a sorting task with 3 options, the top-ranked option earns 3 points. In contrast, if there are 30 options, the highest-ranked option would receive 30 points.
RESULTS
1. Respondents Characteristics
A total of 612 physicians from hospitals in 22 provinces, autonomous regions, and municipalities, along with 1,154 IBD patients seeking medical care in hospitals across 28 provinces, autonomous regions, and municipalities, consented to participate in the survey (Fig. 2), contributing to the final analysis. The survey sample is representative across the dimensions of region, ethnicity, and economic development.
Distribution of hospital regions for physician affiliation and patient visits. This figure was created using software provided by Jianshu Technology.
The characteristics of the respondents are reported in Tables 1 and 2. Among the physician respondents, 427 (69.8%) were gastroenterologists, 172 (28.0%) specialized in ultrasound, and 13 (2.1%) represented other medical specialties. Additionally, 333 (54.4%) physicians held intermediate-level professional designations, and 279 (45.56%) held senior-level professional designations.
Demographic Characteristics of Physician Respondents
Demographic Characteristics, Disease profiles, and Awareness of Patient Respondents
Regarding the patient respondents, 698 (60.5%) were male and 456 (39.5%) were female, with a broad range of ages represented. Of the patients, 820 (71.1%) were diagnosed with CD, 298 (25.8%) with UC, 21 (1.8%) had indeterminate IBD, and 15 (1.3%) were suspected IBD patients.
2. Current Utilization and Implementation of IUS in China
In this study, 424 physician respondents (69.3%) reported being affiliated with hospitals where transabdominal IUS had been implemented (Table 3), with the majority of these hospitals adopting IUS after 2015 (n=338, 79.7%). Implementation was primarily led by radiologists specialized in ultrasound (n=368, 86.8%), and the median year of IUS initiation was 2020. The number of examinations conducted varied significantly across hospitals. Notably, only 79 respondents (18.6%) indicated that their affiliated hospitals had incorporated IUS as a standard diagnostic tool, with an annual usage exceeding 500 cases. However, a considerable portion of respondents reported that IUS was infrequently used in their hospitals, with annual usage ranging from fewer than 100 cases (n=110, 25.9%) to between 300 and 500 cases (n=43, 10.1%). A total of 153 physicians (36.1%) estimated that fewer than 25% of their IBD patients had undergone IUS examinations, while 16.5% of respondents indicated that over 75% of their IBD patients had received the examination.
The Application Status of Transabdominal IUS and Awareness and Knowledge of Physician Respondents
Furthermore, IUS training among physicians remained limited. Based on primary training modality and level of interaction, there were mainly 4 kinds of training commonly practiced in China: conference lectures (lectures delivered during academic meetings, usually with limited interaction and no hands-on component), workshops (typically involve small-group settings with both theoretical and limited practical components, often including simulated cases or equipment demonstration), self-directed learning courses (including online or offline materials that physicians study independently, without real-time instructor feedback or practical engagement), and hands-on practical training (structured, mentor-guided sessions in which trainees operate ultrasound equipment on real patients or models under supervision, offering the most direct practical skill acquisition). Only 166 physician respondents (27.1%) reported having received formal training (Table 3). The most common modes of such training were conference lectures for gastroenterologists and workshops for radiologists, and only 48 individuals (28.9%), the majority of whom were radiologists specialized in ultrasound, had received hands-on operational training.
Correspondingly, 687 patient respondents (59.5%) reported having undergone transabdominal IUS examinations and they received IUS at intervals ranging from less than 3 months to more than 1 year (Table 2). Prior to the examination, most patients were informed about the indications for IUS examination (n=486, 70.7%), the necessity of preparatory measures such as fasting (n=577, 84.0%). Overall, most patients were satisfied (n=357, 52.0%) or very satisfied (n=166, 24.2%) with IUS. In terms of safety and comfort, 885 patients (76.7%) described IUS as either “safe” or “very safe”, and 583 (50.5%) regarded it as the most acceptable procedure for routine examinations (Table 2). However, although 701 patients (60.8%) reported no concerns, a considerable portion expressed worries about intestinal infection (n=254, 22.0%), intestinal perforation (n=250, 21.7%), and intestinal bleeding (n=308, 26.7%) (Table 2).
3. Awareness of IUS in IBD Management
A total of 91.7% of physicians expressed an intention to incorporate IUS into their future practice for diagnosing and monitoring IBD. Among them, 530 physicians regarded IUS as either “important” (n=273, 44.6%) or “extremely important” (n=257, 42.0%). Physicians demonstrated strong support for IUS in various clinical scenarios, with high acceptance rates for its use in differentiating gastrointestinal diseases (n=498, 83.7%), monitoring IBD disease activity (n=554, 92.3%), assessing therapeutic efficacy in IBD (n=539, 90.4%), and evaluating IBD-related gastrointestinal complications (n=554, 93.0%). However, only 398 physicians (72.2%) endorsed its use for evaluating dysregulated gastrointestinal motility (Fig. 3). Notably, a significantly larger proportion of radiologists specialized in ultrasound compared with gastroenterologists supported the use of IUS in differential diagnosis (93.5% vs. 79.8%, P=0.003) and gastrointestinal motility evaluation (84.0% vs. 67.3%, P=0.023) (Table 3).
Physicians’ perception of transabdominal intestinal ultrasound application scenarios.
Regarding the recommended intervals for IUS assessments in IBD patients, approximately 30% of physicians believed that IUS should be employed to assess therapeutic efficacy in active IBD patients at 4 weeks (n=215, 35.1%) and 3 months (n=188, 30.7%) following induction therapy. For patients in remission, about 30% of physicians recommended IUS evaluation every 3 months (n=218, 35.6%) or every 6 months (n=177, 28.9%). More radiologists favored recommended earlier IUS evaluation at 2 weeks post-treatment initiation for active patients (25.6% vs. 8.0%, P<0.001) and more frequent monitoring (every month) for patients in remission (12.8% vs. 3.0%, P<0.001).
4. Perceived Benefits and Limitations of IUS
As shown in Fig. 4, the 3 most recognized advantages ranked by physicians were “non-invasiveness” (5.98), “low-cost” (5.39), and “high patient-acceptance” (4.72). Conversely, the top 3 disadvantages identified were “operator experience-dependent” (6.99), “insufficient sensitivity in deep pelvic bowel exploration” (5.00), and “high interoperator variability” (4.49). From patients’ perspective, most considered IUS as the most convenient (n=867, 75.1%), most comfortable (n=800, 69.3%), most cost-effective (n=683, 59.2%), with the shortest appointment times (n=767, 66.5%), and non-radiative (n=783, 67.9%) compared to other diagnostic modalities (Fig. 5). Given these perceived advantages, 583 individuals (50.5%) chose IUS as their preferred examination. Additionally, patients were willing to undergo IUS at significantly shorter intervals than other imaging modalities, such as colonoscopy, CTE, and MRE (Fig. 6).
Strengths and disadvantages of transabdominal intestinal ultrasound ranked by physicians.
Advantages of transabdominal intestinal ultrasound (IUS) compared with other examinations from perspectives of patients.
The interval at which patients are willing to undergo regular examinations. IUS, intestinal ultrasound; MRE, magnetic resonance enterography; CTE, computed tomography enterography.
5. Physicians’ Knowledge Repository Related to IUS
When asked to identify the most sensitive imaging modality for assessing disease activity among IUS, CTE, and MRE, physicians selected CTE (n=232, 37.9%) and MRE (n=233, 38.0%) at nearly equivalent rates (Fig. 7). Most physicians identified MRE as the most sensitive modality for determining intestinal fistula (n=325, 53.1%), detecting intestinal wall fibrosis (n=298, 48.7%) and evaluating therapeutic efficacy (n=198, 32.3%). Regarding the diagnosis of abdominal abscess, one-third of physicians considered IUS (n=208, 34.0%), CT (n=169, 27.6%), and MRE (n=201, 32.8%) to be the most sensitive modality, respectively. Notably, radiologists specialized in ultrasound were more likely than gastroenterologists to consider IUS sensitive for assessing treatment efficacy (48.3% vs. 19.4%, P<0.001), intestinal wall fibrosis (33.7% vs. 27.4%, P<0.001), intestinal fistula (27.9% vs. 11.2%, P<0.001), abdominal abscesses (49.4% vs. 28.6%, P<0.001), and disease severity (30.2% vs. 11.0%, P<0.001). Regarding the IUS evaluation criteria for IBD, 365 physicians (59.6%) correctly identified the indicators of the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS), while only 27 (4.4%) were familiar with the Milan Ultrasound Criteria (MUC) for diagnosing UC.
Physicians’ comparison of different examination. CTE, computed tomography enterography; MRE, magnetic resonance enterography; IUS, intestinal ultrasound; NS, not significant. **P<0.01; ***P<0.001.
6. Barriers to IUS Adoption and Recommendations for Improvement
The primary barriers to implementing IUS in patients with IBD were predominantly related to insufficient operator training, which was cited by 86.4% of physician respondents (Table 3). Other significant challenges included inadequate manpower (50.8%) and low awareness of IUS application, (52.1%). Issues related to inadequate equipment were mentioned by 35.5% of respondents, while patient acceptance was a minimal concern, representing only 9.97% of barriers. Notably, 548 physicians (89.5%) expressed willingness to participate in further IUS training. In the final section of the survey, 126 physicians provided thoughtful suggestions for promoting IUS, with a strong emphasis on the standardization of raining and the establishment of operational and quality control standards for IUS.
DISCUSSION
IBD is a chronic, lifelong condition that requires regular disease assessment. Transabdominal IUS has emerged as a noninvasive, non-radiative and low-cost tool to determine disease activity, extent and predict outcomes without bowel preparation in numerous intestinal diseases, especially IBD [3]. This nationwide survey highlight the growing recognition of IUS as a valuable diagnostic and monitoring tool for IBD, as perceived by both physicians and patients across China. The survey results show that more than two-thirds of physicians reported the availability of IUS in their hospitals, but its utilization varied significantly across hospitals. Over a quarter of physicians indicated less than 100 cases were conducted annually at their hospitals, and more than a third used IUS in less than 25% of their IBD patients. Only a quarter of physicians had received IUS-specific training. The majority of patients who underwent IUS were highly satisfied with the experience.
Despite increasing adoption of IUS in recent years, considerable variability in its usage remains across hospitals, with a significant number of physicians infrequently ordering IUS examinations for their patients. Several factors may hinder the utility of IUS. First, insufficient physician training is a major barrier. Although there has been an increasing number of national and international IUS training programs held recently, a significantly low proportion of physicians are receiving formal training. In China, structured IUS training initiatives have been launched by Chinese IUS Group in collaboration with the IBD Group of the Chinese Society of Gastroenterology since 2023, with national workshops and conference-based sessions progressively expanding education and awareness among over 200 physicians. International endeavors toward standardization, such as the certification programs formulated by IBUS and GENIUS, also signify crucial strides in ensuring quality and consistency in IUS practice. Although such international certification programs are gaining recognition, they remain underutilized in China, largely due to limited access, language barriers, and a lack of localized training infrastructure. In this study, only 27.1% of physicians having received formal IUS training. Gastroenterologists primarily train through conferences, while radiologists specialized in ultrasound receive more hands-on training, contributing to divergent perceptions of IUS utility. For instance, gastroenterologists underestimated IUS’s sensitivity for detecting abdominal abscess. Second, the lack of standardized protocols for IUS implementation limits its clinical adoption. Variations in inspection procedures, such as inconsistent bowel preparation and lack of standard diagnostic criteria undermine diagnostic consistency. This aligns with concerns from the American Gastroenterological Association regarding the absence of universally accepted guidelines [13]. Establishing evidence-based protocols for bowel preparation, image acquisition, and measurement systems could improve diagnostic consistency [10]. Third, inadequate patient education diminished IUS acceptance and adherence. Despite high satisfaction (74.1%) with IUS experience, 26.7% of patients expressed unwarranted concerns about complications (intestinal perforation, intestinal bleeding and intestinal infection). Similar to how some patients mistakenly associate MRE with radiation exposure, certain respondents in our study may have confused IUS with more invasive procedures, such as colonoscopy or endoscopic biopsy. This misunderstanding is particularly plausible considering that nearly 40% of patient respondents had never undergone an IUS examination, which may limit their familiarity with its safety and advantages. Rather than indicating real procedural risks, these concerns highlight the need for enhanced patient education efforts in China, especially for emerging or underutilized diagnostic tools such as IUS.
Significant disparities were observed between gastroenterologists and radiologists in their perceptions of IUS applications. Radiologists specialized in ultrasound favored IUS for differential diagnosis and gastrointestinal motility assessment more than gastroenterologists, and they recommended earlier and more frequent IUS assessments for IBD patients. They also considered IUS more sensitive for various aspects of disease monitoring, while gastroenterologists tended to rely more on CTE or MRE. Studies show that when performed by well-trained practitioners, IUS provides comparable accuracy to MRE and CTE for defining disease activity of the ileum [13]. A systemic meta-analysis also demonstrated the diagnostic accuracy of IUS for suspected CD (sensitivity 0.84, specificity 0.92) and high accuracy in identifying complications such as fistulas, abscesses and stenosis (both sensitivity and specificity exceeding 80%) [16]. For colonic diseases, IUS even showed higher sensitivity than MRE [13]. These disparities likely stemmed from differences in training and professional backgrounds. Therefore, insufficient physician training, identified as a major barrier to IUS implementation, needs to be addressed. It is recommended to include clinical scenario-based IUS training courses for gastroenterologists, while radiologists should receive additional training on practical techniques, such as assessing disease activity using IUS.
From the patients’ perspective, they expressed the highest acceptance of IUS among routine examinations. As expected, the acceptable intervals for IUS in routine follow-up were much shorter than those for other imaging modalities. However, despite the majority of patients undergoing IUS and expressing satisfaction, some still stated concerns about complications, suggesting a lack of complete understanding about the safety of IUS. This is likely due to insufficient communication from physicians on the implications and safety of IUS. Rohatinsky et al. [17] found that IBD patients’ preference for noninvasive tests positively correlates with their understanding of the technical aspects. Therefore, visual educational tools like animations explaining the noninvasive nature of IUS and structured communication checklists covering examination purposes, preparation, and risk clarification should be implemented to improve patient awareness.
This study has several limitations. Due to privacy concerns, we did not collect detailed information about the affiliated hospitals of the physician respondents, limiting our ability to directly analyze IUS application at the institutional level. Additionally, we received a limited number of responses from physicians in western China, which may have introduced a degree of selection bias, potentially affecting the regional representativeness of our findings. For instance, the observed discrepancy in awareness between IBUS-SAS and MUC may stem from regional and disease-specific factors. Despite our efforts to ensure the representativeness of the sample, most physician respondents were from southern and eastern China, where CD is more prevalent, and about 70% of patient respondents had CD. As IBUS-SAS is primarily designed for assessing small bowel inflammation, its greater familiarity in CD-predominant settings is expected. This also reflects a potential under-recognition among physicians regarding the clinical value of IUS in UC management. Besides, patient feedback on IUS was based on recall, which might introduce reporting biases. Future studies should aim to address these gaps by incorporating more comprehensive data collection and ensuring balanced regional participation to provide a more holistic understanding of IUS implementation across the country.
In summary, this study provides a comprehensive overview of the current utilization, perception, and knowledge about IUS of physicians and patients in the diagnosis and management of IBD across China. Despite growing recognition of IUS in China, its wide utilization in IBD management, especially for disease monitoring, requires further promotion. The notable disparity between gastroenterologists and radiologists specialized in ultrasound regarding IUS application scenarios, diagnostic efficacy, and clinical knowledge underscores the need for targeted, specialty-specific training to optimize its use in IBD management. Additionally, strengthening patient education efforts is essential to further enhance patient acceptance with IUS.
Notes
Funding Source
This work was supported by Natural Science Foundation of Beijing (grant number: 7252104) and Beijing Health Technology Promotion Project (grant number: BHTPP2024096, BHTPP P2024097).
Conflict of Interest
Li Y has received research grants from Natural Science Foundation of Beijing and Zhu Q has received research grants from Beijing Health Technology Promotion Project. The other authors have no conflicts of interest to declare.
Data Availability Statement
The data underlying this article are available in the article and in its online supplementary material.
Author Contributions
Conceptualization: Yun L, Wang Z, Chen Y (3rd), Chen N, Chen Y (5th), Zhang X, Mao R, Li Y, Zhu Q, Chen M. Data curation; Investigation: Chen Y (3rd), Chen N, Chen Y (5th), Zhang X, Mao R. Data interpretation; Formal analysis: Yun L, Wang Z, Zhu Q, Xie X, Chen M. Funding acquisition: Li Y, Zhu Q. Methodology: Yun L, Wang Z, Chen Y (3rd), Chen N, Chen Y (5th), Zhang X, Mao R, Li Y, Zhu Q, Chen M. Project administration: Li Y, Chen M. Resources: Chen Y (3rd), Chen N, Chen Y (5th), Zhang X, Mao R. Software: Yun L, Wang Z, Zhu Q, Xie X. Supervision: Chen Y (5th), Zhu Q, Chen M. Validation: Wang Z, Zhu Q, Chen M. Visualization: Yun L, Wang Z. Writing – original draft: Yun L, Wang Z, Li Y. Writing – review & editing: Yun L, Wang Z, Chen Y (3rd), Chen N, Chen Y (5th), Zhang X, Mao R, Li Y, Zhu Q, Chen M. Approval of final manuscript: all authors.
Supplementary Material
Supplementary materials are available at the Intestinal Research website (https://www.irjournal.org).