Maintaining regular function of the intestinal tract is an important prerequisite for successful outcomes in critical illness. Disturbances of gastrointestinal motility are frequently caused by drugs, excessive fluid load, mechanical ventilation, surgical or ischemic damage, and occur frequently in sepsis and SIRS. Impaired gastrointestinal motility may give rise to a vitious circle of enteral nutrition intolerance, edema, and may eventually result in a breakdown of the gastrointestinal barrier. Early diagnosis, patient-adapted treatment and a focus on prophylactic measures are necessary prerequisites to maintain gut function in critically ill patients.