This document provides guidance on how to design and conduct a complex literature search to review information on the use of vedolizumab for Crohn's disease. It outlines researching the question using PICO (population, intervention, comparator, outcome), reviewing background literature like systematic reviews and clinical trials, searching relevant bibliographic databases like Medline and grey literature sources, and provides an example search strategy and results for Medline. The goal is to conduct a thorough search across multiple information sources to identify all relevant evidence on this topic.