PREFACE Oxidative stress is a feature of gastrointestinal diseases and associated conditions, affecting a variety of molecular and cellular processes that ultimately contribute to the disease pathophysiology. Oxidative stress can arise due to nutritional imbalance during a spectrum of time frames, before the onset of disease, or during its development. Considering these premises, there is a fundamental need to better understand the processes inherent to oxidative stress in gastrointestinal tissues, and to evaluate whether oxidative stress can be ameliorated with pharmacological or natural agents with antioxidant properties. Importantly, whilst physicians and clinical workers understand the cellular processes involved in gastrointestinal di...