Gastrointestinal diseases are widespread in patient populations across the globe, affecting both developed and developing nations. But since organs of the gastrointestinal tract are well protected within the body, symptoms may take months or even years to develop and be seen in a clinical setting. It makes sense that the skin, as the largest organ, would show manifestations of gastrointestinal disease. At times, it is the cutaneous symptom that would give a doctor the first indication of the presence of an otherwise hidden gastrointestinal disease. The following sections describe major cutaneous symptoms of Gastrointestinal diseases, including Inflammatory Bowel Diseases, Celiac Disease, Liver Cirrhosis, and Hepatitides (A-E). In many cases, the skin lesion can be treated by addressing the Gastrointestinal disease that causes it, but some require their own treatment. Inflammatory bowel diseases (IBDs) have multiple dermatological manifestations, including Pyoderma Gangrenosum, Erythema Nodosum, Aphthous Stomatitis and Psoriasis. Current and new developments in treatment for both psoriasis and the underlying IBDs will be discussed. Celiac Disease can be accompanied by Dermatitis Herpetiformis, a potentially debilitating and painfully pruritic skin rash. Skin manifestations of Liver Cirrhosis are wide ranging and once seen, are a true harbinger of serious liver disease. Lastly, viral hepatitides, especially Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV), can also exhibit skin symptoms. Porphyria Cutanea Tarda is well known for being associated with HCV. This thesis will discuss skin manifestations of different gastrointestinal diseases, as well as standard, newly approved, and developing treatments that address the cutaneous symptom and underlying disease.