Mastocytosis is a rare and heterogeneous disease characterized by various biological and clinical features with different prognosis and treatments. The disease is usually divided into 2 categories: a pure cutaneous and a systemic disease. Clinical features can be related to mast cells' mediators release or to pathological mast cells infiltration. The diagnosis of mastocytosis is based on clinical, biological, histological, and molecular international criteria. Among all manifestations of the disease, gastrointestinal (GI) symptoms are common and can significantly impair the quality of life. The aim of this article is to review the data regarding GI involvement in mastocytosis. Articles dealing with clinical, pathophysiological, and therapeutic aspects of mastocytosis GI tract involvement were searched for using PubMed. GI manifestations in mastocytosis are reviewed. Pathogenesis of GI symptoms in systemic mastocytosis and their treatment are critically discussed. The most frequent GI symptoms are abdominal pain, diarrhea, nausea, and vomiting. GI lesions may involve all the digestive tract, from the esophagus to the rectum. The histological diagnosis of GI involvement is difficult. The treatment of GI symptoms aims to prevent and limit mast cells degranulation and/or its consequences and more rarely to control tumoral mast cells infiltration. The high prevalence of GI symptoms in mastocytosis and their important functional impact deserves better characterization and treatment in order to improve patients' quality of life. Diagnosis of mastocytosis GI manifestations should be evoked in the case of unexplained severe GI disorders.