Aim. Gastrointestinal occult bleeding (OGB) is defined as persistent or recurrent bleeding from the gastrointestinal tract in which the source has not been identified endoscopically. New advances in small bowel diagnostics and the ability to successfully perform endoscopic therapy have largely replaced surgical procedures and have led to a trend towards non-invasive diagnosis and endoscopic treatment of OGB. The purpose of this literature review is to study the current state of diagnosis and treatment of occult gastrointestinal bleeding.Materials and methods. An electronic literature search was carried out using databases: PubMed, Medline, Cochrane Library.Results. This literature review includes systematic reviews and meta-analyses, prospective and retrospective studies, and literature reviews.Conclusion. The introduction of new methods of imaging and endoscopy has contributed to a significant improvement in the effectiveness of methods for diagnosing and treating occult bleeding.