Gastrointestinal disturbances, such as diarrhea, nausea, abdominal pain, and vomiting, are very common because erythromycin is a motilin agonist.[3] Because of this, erythromycin tends not to be prescribed as a first-line drug. However, it may be useful in treating gastroparesis due to this promotility effect. Intravenous erythromycin may also be used in endoscopy as an adjunct to clear gastric contents.