The decision how to handle an antithrombotic treatment when an intervention during GI endoscopy is planned is influenced both by the risk of bleeding and by the thromboembolic risk when treatment is suspended. The risk of bleeding is negligible even when on oral anticoagulants in diagnostic procedures with standard forceps biopsies. Oral anticoagulation has to be stopped, however, when planning invasive procedures such as polypectomy or EPT. In the case of patients with a high risk of thromboembolic complications such as artificial valves in mitral position or atrial fibrillation with risk factors, one has to temporarily switch to anticoagulants with shorter action ("bridging"). Treatment with inhibitors of platelet function does not preclude procedures with a low risk of bleeding including forceps biopsy. Urgent procedures with a high risk of bleeding should be performed after stopping clopidogrel one week previously but only after consultation with the treating cardiologist. In the case of colonoscopy, in particular as a screening procedure, there are two options: 1) stopping oral anticoagulation (with or without bridging) or clopidogrel, respectively, or 2) continuing antithrombotic treatment and performing a second elective endoscopy for polypectomy with tapered antithrombotic medication if polyps are found which are not amenable to resection by biopsy forceps. The choice between these two options has to be made individually.