[Incidental findings in gastroscopy and colonoscopy]

For many specific and nonspecific gastrointestinal symptoms, endoscopic diagnostic procedures play an important role. Gastroscopy and colonoscopy are easily available diagnostic and interventional procedures with low risk. The technical development of gastrointestinal endoscopy has led to an improvement in diagnostics and therapy. In addition to frequent and expected findings, incidental findings may occur. The incidental findings can distinguish rare diseases of unexpected diagnoses. Rare diagnoses usually require an individualized therapy. Unexpected diagnoses can take place during (not properly detected) or after an endoscopy (overlooked or newly appeared) occur. This overview deals with the question of how to minimize unexpected diagnoses and how to diagnose and treat incidental findings.