The gastrointestinal tract is a passage way containing major organs of the digestive system from mouth to anus. The digestive system in humans comprises the gastrointestinal tract along with the accessory organs including the gallbladder, pancreas, salivary glands, liver and tongue. One of the significant diseases associated with gastrointestinal tract is the liver disease. Upset stomach and nausea are signs of liver disease. As the ability of the liver to take out the toxins decreases; it increases the digestive distress. Liver disorders can be genetic or caused due to viral infections, alcohol use and even obesity. Primary cancers of the gastrointestinal tract can eventually metastasize and cause secondary lesions or liver malignancies. One of the significant mechanisms that cause liver diseases is DNA damage. Diagnostic tests like liver function test, which are a group of blood tests, can be used to examine the proper functioning of liver. This book unravels the recent studies on gastrointestinal tract and liver diseases. Also included herein is a detailed explanation of the diagnosis, mechanisms and treatment of these diseases. This book is a resource guide for experts as well as students.