AbstractIntroduction:School students often carry heavy school bags, which can contribute to various health issues, including abdominal pain. The relationship between heavy school bags and abdominal pain is an emerging concern among educators, healthcare professionals, and parents. Excessive weight from school bags is known to place strain on students’ musculoskeletal systems, leading to discomfort, including abdominal pain. Despite growing concerns, there is a lack of research on using the Visual Analog Scale (VAS) to assess abdominal pain specifically among school students. This study investigates the reliability and validity of the VAS for measuring abdominal pain in school students, with the goal of improving pain assessment practices in this population.Objectives:Assess the validity of VAS scores for acute abdominal pain in school students. Determine the reliability of VAS scores for acute abdominal pain. Identify the minimum clinically significant difference in abdominal pain as measured by VAS.Methods:This prospective cohort study included school students aged 10-18 years in Kanyakumari District, Tamil Nadu. A multistage sampling method, followed by simple random sampling, was employed to select participants. A total of 200 students participated after accounting for a 10% loss to follow-up. The study involved two phases: an initial assessment using the VAS and standardized health questionnaires, followed by a follow-up assessment after two weeks for test-retest reliability. Data on demographics, pain intensity, and health history were collected, and reliability and validity testing were performed using statistical methods like Cronbach’s alpha, Intraclass Correlation Coefficient (ICC), and Pearson’s correlation coefficient.Results:The mean age of participants was 12.03 years (SD = 3.2), with a gender distribution of 54.5% female and 45.5% male. The VAS demonstrated high test-retest reliability (ICC = 0.87), indicating that it is a stable tool for assessing abdominal pain over time. A moderate positive correlation was found between age and pain intensity (r = 0.65, p < 0.001), suggesting that older students reported higher levels of abdominal pain. There were no significant gender-based differences in pain intensity (p > 0.05).Discussion:The study confirmed that the VAS is a reliable and valid tool for assessing abdominal pain in school students. The high ICC supports its consistency across different time points, and the correlation analysis suggests that the VAS is sensitive to varying levels of pain intensity related to age. These findings align with previous research validating the VAS in pediatric populations for different types of pain.Limitations:The study’s generalizability is limited to school students in Kanyakumari District and may not apply to other regions. Self-reporting of pain through VAS could introduce reporting biases, and follow-up attrition may have affected the reliability estimates. Additionally, variability in students’ cognitive understanding of the VAS could influence the accuracy of their responses.Conclusion:The VAS is a reliable and valid instrument for assessing abdominal pain among school students in Kanyakumari District. Its use can aid in early detection and intervention of abdominal pain, contributing to improved health outcomes in this population. Further studies are needed to explore the VAS’s applicability in other populations and settings to broaden its utility.