INTRODUCTION. Irritable bowel syndrome (IBS) is a chronic functional disorder present in over 13% of the population. Despite the wide prevalence of IBS, there is currently a lack of well characterised authorised medicinal products to treat IBS. This situation stems from both poor engagement in the development of such medicinal products and the absence of sound approaches to their regulatory review. The intensification of drug development aimed at improving the safety and efficacy of IBS therapy in the context of the growing common pharmaceutical market of the Eurasian Economic Union (EAEU) requires guidelines for planning and conducting clinical trials of medicinal products for IBS.AIM. This study aimed to evaluate the possibility of using the methodological approaches described in international guidelines for the development of national recommendations for conducting clinical trials of medicinal products for IBS.DISCUSSION. The authors analysed the main provisions of the Guideline on the evaluation of medicinal products for the treatment of IBS by the European Medicines Agency (EMA). The analysis identified the methodological tools, the scope and stages of clinical trials, and the efficacy criteria for each study stage. The authors assessed the specific aspects of diagnosing IBS, which are considered when determining the effectiveness of therapeutic interventions. This review highlighted the need for the harmonisation of national and international methodological approaches to the evaluation of clinical trial results that would ensure more robust results of clinical trial reviews conducted in different countries. The authors determined the considerations for planning exploratory and confirmatory clinical trials, including the selection of endpoints, design, and duration of clinical trials in adults and children, as well as the sex distribution of the trial population.CONCLUSIONS. The EMA’s recommendations may guide the planning of clinical programmes for novel medicinal products for IBS. These recommendations may be applied by experts reviewing clinical trial results, as well as developers creating new medicinal products.

INTRODUCTION. Chronic constipation is a widespread condition associated with substantial direct and indirect costs for diagnosis and treatment and a significant reduction in the quality of life of patients. There is a need for the development and clinical studies of novel medicinal products for chronic constipation due to the limited availability of effective treatment options and concerns regarding the long-term safety and tolerability of these options. Currently, the Russian Federation and other Member States of the Eurasian Economic Union (EAEU) lack guidelines governing the design and conduct of clinical trials of new medicinal products for chronic constipation.AIM. This study aimed to analyse the relevant international approaches and methods as a potential basis for drafting a regional guideline for planning clinical trial programmes for novel medicinal products for chronic constipation.DISCUSSION. This study analysed the main provisions of the European Medicines Agency (EMA) outlined in the Guideline on the evaluation of medicinal products for the treatment of chronic constipation (including opioid-induced constipation) and for bowel cleansing. The authors identified special considerations for conducting pharmacology studies and confirmatory clinical trials (selection of the clinical trial population, design, and duration; selection of primary and secondary efficacy endpoints; and safety assessment). Additionally, the authors highlighted special considerations for confirmatory clinical trials in paediatric and geriatric populations.CONCLUSIONS. The EMA guideline covers all the requirements that are necessary for designing a clinical trial programme for a novel medicinal product for chronic constipation. Therefore, the EMA guideline can inform the ongoing development of the corresponding guideline for the Russian Federation and other EAEU Member States.

INTRODUCTION. Colon cleansing plays an essential role in preparation for diagnostic procedures and surgical interventions. One of the key factors ensuring high-quality colon cleansing is the correct choice of a medicinal product that affects the intestinal contents and removes them from the body. Planning and conducting clinical trials for new effective colon cleansing medicines that are well-tolerated and have a favourable safety profile is an urgent task for health care. Currently, there are no regulatory documents on planning a clinical trial programme for colon cleansing medicinal products in the Russian Federation or the Eurasian Economic Union. AIM . This study aimed to prepare recommendations for planning a clinical trial programme for bowel cleansing medicinal products. DISCUSSION. Main provisions of the Guidelines of European Medicines Agency (EMA) were analysed for new medicinal products used in chronic constipation. The Guidelines define specific conditions for pharmacological studies and confirmatory clinical trials (regarding choice of design, study population, criteria for assessing efficacy and safety), as well as specific requirements for clinical trials in paediatric and elderly patients. Particular features of clinical trials for bowel cleansing medicines include patients with no comorbidities other than bowel disease; confirmatory clinical trials designed as randomised, active-control studies in parallel groups; safety assessment for a single-use medicinal product; long-term safety studies not required. CONCLUSIONS. The main research models described in EMA Guidelines on clinical trials of bowel cleansing medicinal products enable a reliable assessment of safety and efficacy of the above medicines and can serve to prepare guidelines on clinical trial planning for bowel cleansing medicinal products.