Dermatological manifestations can serve as an early indicator of gastrointestinal diseases, enabling prompt diagnosis and treatment, and potentially reducing patient morbidity and mortality. They can also arise as complications of already recognized gastrointestinal diseases, further complicating the patients' condition. The most common skin manifestations of celiac disease are dermatitis herpetiformis and psoriasis, and their symptoms significantly improve with the introduction of a glutenfree diet. Inflammatory bowel diseases are becoming increasingly prevalent in the developed world. Skin changes associated with inflammatory bowel diseases encompass a wide spectrum of pathological conditions that can range from mild clinical manifestations to very severe and challenging to treat cases. Diseases where gastrointestinal bleeding is a prominent symptom can initially manifest through changes in the skin. Recognizing these skin manifestations allows for earlier diagnosis and timely treatment, preventing the development of gastrointestinal complications. Nutrient deficiencies, which can present as changes in the skin, nails, and hair, are often caused by malabsorption syndrome. Hereditary gastrointestinal cancer syndromes are present in about 20% of colorectal cancer cases diagnosed before the age of 50. Early detection of skin manifestations in these syndromes leads to a significant reduction in patient mortality. Paraneoplastic dermatoses are a heterogeneous group of skin diseases that usually accompany the clinical course of an underlying malignant disease. Thus, curing the malignant disease also leads to the regression of paraneoplastic skin changes. Gastrointestinal tumors that secrete hormones can, in addition to typical systemic symptoms, lead to skin manifestations such as erythema as part of carcinoid syndrome. The purpose of this paper is to provide an overview of the dermatological manifestations of the aforementioned gastrointestinal system diseases. Highlighted are prominent epidemiological data, the etiology and pathogenesis of the diseases, diagnostic methods, and treatment, with a particular focus on clinical presentation.