Relationship Between Interoception and Postural Control in Constipation-Predominant Irritable Bowel Syndrome

This study is designed as a cross-sectional, observational, controlled comparative study. The study population will consist of individuals aged 18-45 years with a diagnosis of constipation-predominant irritable bowel syndrome (IBS-C) and healthy volunteers with similar age and sex characteristics.

The sample size was calculated using G*Power 3.1.9.7 based on a medium effect size (d=0.50), a significance level of 5% (α=0.05), and a statistical power of 80% (1-β=0.80). A total of 128 participants, with at least 64 participants in each group, are planned to be included.

After written informed consent is obtained, participants will complete a sociodemographic information form. Interoceptive awareness will be assessed using the Multidimensional Assessment of Interoceptive Awareness-2 (MAIA-2). Stool type will be evaluated using the Bristol Stool Scale in the IBS-C group, and posture will be assessed in all participants using the Corbin Posture Analysis.

The collected data will be analyzed using descriptive statistics, tests of normality, between-group comparison tests, correlation analyses, and multivariable regression analyses. Statistical significance will be set at p<0.05.

Primary outcomes

• Interoceptive Awareness [Baseline (single assessment at study enrollment).]: Interoceptive awareness will be assessed using the Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), a 37-item self-report questionnaire with 8 subscales (Noticing, Not-Distracting, Not-Worrying, Attention Regulation, Emotional Awareness, Self-Regulation, Body Listening, Trusting). Each item is rated from 0 (never) to 5 (always), and the unit of measure is the mean score of each subscale (range 0 to 5). Higher scores indicate better interoceptive awareness.
• Postural Characteristics [Baseline (single assessment at study enrollment).]: Posture will be assessed by an examiner using the Corbin Posture Analysis, an observational posture evaluation in which body segments are rated against a standard postural alignment. The unit of measure is the total posture score (range: 0 to 20). Higher scores indicate worse posture.

Sex: All, ages: 18 Years to 45 Years, accepts healthy volunteers

Inclusion Criteria:

* Aged 18-45 years.
* For the IBS-C group, having a clinical diagnosis of constipation-predominant irritable bowel syndrome.
* For the control group, having no history of gastrointestinal disease.
* Voluntarily agreeing to participate in the study.

Exclusion Criteria:

* Having a neurological, rheumatological, or serious orthopedic disease.
* Having a history of surgery that may affect posture.
* Pregnancy.
* Being unable to complete the assessments due to cognitive or communication impairment.

• Gamze Koyutürk, Asst Prof, Principal investigator, Topkapı University
• Mehmet B Uyaroğlu, Asst Prof, Study director, Fenerbahce University
• Görkem Dizdar, Asst Prof, Study chair, Topkapı University
• Mehmet M Atasoy, Prof, Study chair
• Beyza Erdogmus, Dr, Study chair