The human digestive system consists of a long tube known as the gastrointestinal (GI) tract plus the accessory organs of digestion. The GI tract is divided into several parts, each with special characteristics: the mouth, esophagus, stomach, and small and large intestines. In addition, there are also accessory glands associated with this system, such as: liver, pancreas, and gallbladder. The main function of GI tract is the digestion of foods to become simpler molecules suitable for absorption to provide the nutrients necessary for normal functionality of the body. There are several disorders that affect the human digestive system and many of them have a high prevalence worldwide and have become increasingly common over the last few years. Digestive diseases range from the occasional upset stomach to the more life-threatening colon cancer and encompass disorders of the GI tract, liver, gallbladder, and pancreas.

The current approved treatments for many digestive diseases are inefficient or associated with side effects. For example, proton pump inhibitors (omeprazole, lansoprazole) may cause nausea, abdominal pain, constipation, and diarrhea, and H2 receptor antagonists (ranitidine) may suffer loss of effectiveness due to tolerance. For this reason, the attention of the scientific community has been directed towards the search for new therapies in the treatment of such diseases. There have been many experimental and clinical studies emerging during the last decade looking to investigate the potential application of herbal products, mainly medicinal and/or edible plants, to prevent or treat these disorders when used either as complementary or alternative treatments. The results of such studies have reinforced the importance of herbal preparations for the development of new drugs to treat such disorders and have shown their adjuvant role in enhancing the effectiveness of the approved treatment in progress.

However, despite popular use, different plant species still lack scientific contributions to validate their use. Therefore, this Special Issue aims to bring together articles that promote the discussion of the therapeutic value of medicinal and edible plants in digestive system diseases. We aim to highlight research that can contribute to the improvement and innovation of clinical practice within gastroenterology. Original research and review articles are welcome.

Potential topics include but are not limited to the following:

• Studies at both the experimental, pre-clinical and clinical level concerning the potential role of plant extracts used in folk medicine or from edible plants to prevent or treat gastroesophageal reflux disease, gastritis, and gastric ulcers
• The potential role of plant extracts used in folk medicine or from edible plants to treat Crohn's disease, alimentary mucositis, irritable bowel syndrome, and gallstones
• The treatment of diseases of the liver, such as hepatitis and liver damage, using plant extracts or edible plants
• Investigations concerning isolated compounds from natural sources to prevent or treat digestive system diseases
• Safety of plant extracts or isolated active compounds in the digestive system