Clinical research plays a vital role in improving the care and outcomes of patients with IBD. Through research, clinicians and researchers can gain a better understanding of the disease process, develop new therapies, and improve existing therapies. Clinical research also enables the identification of biomarkers and other diagnostic tools that can aid in early detection and personalized treatment strategies. Ultimately, the goal of clinical research in inflammatory bowel disease (IBD) is to improve patients’ quality of life and reduce the burden of this challenging disease. Without ongoing research efforts, advances in IBD care would be limited and patients would continue to face significant health challenges. The study team may include investigators, nurses, study coordinators, pharmacists, statisticians, and data managers. Each team member has a specific role and responsibilities that must be clearly defined and communicated to ensure smooth and effective study conduct. The trial must be conducted in accordance with regulatory requirements and standard operating procedures, and participants must be treated with care and respect. This chapter looks at the main trial designs, trial terminology, and: