Previous research has purported a high prevalence of eating disorders, most notably Avoidant/Restrictive Food Intake Disorder, among adults with irritable bowel syndrome (IBS). Despite this, there appears to be no validated tool to screen for eating disorders in the IBS population, or a clear consensus as to which screening tools are the most appropriate to use within this population. This thesis aimed to explore eating disorder screening tools used or suggested within this population amongst the literature and help to improve identification of Avoidant/Restrictive Food Intake Disorder (ARFID) in those with IBS. Part one of this portfolio presents a scoping review of screening tools that have been suggested or used in the literature to screen for eating disorders within the IBS population. The results of the review suggested that no single screening tool or method are being used within the research, with a lack of detailed information relating to the screening tool being reported, such as demographic information, psychometric properties, and time taken to complete the measure. Part two presents an empirical paper that explored the reliability and validity of a pre-existing and validated ARFID screen, the Nine-item ARFID Screen (NIAS), within the IBS adult population. The results suggested good internal reliability, convergent validity, and model fit for this measure within this population. However, the findings indicated a lack of discriminant validity, therefore further evaluation of this screening tool within this population is required, addressing the limitations outlined within the study.