Background: Few prokinetic drugs are available to treat gastroparesis. Data are limited on short-term and long-term efficacy of erythromycin as a prokinetic drug. Goals: Assess efficacy of low-dose erythromycin suspension to treat gastroparesis. Study: Patients with dyspepsia and gastroparesis by gastric emptying study were treated with low-bulk diet and low-dose (50-100 mg 3 times a day and at bedtime) oral erythromycin suspension. Data were collected by retrospective chart review and telephone questionnaire for short- and long-term follow-up, respectively. Results: Of 25 patients, 18 had short-term follow-up, 18 had long-term follow-up, and 14 bad both. On short-term follow-up, 15 patients (83%) experienced some or dramatic improvement, while 3 (17%) experienced worsening or no change in symptoms (P = 0.005). Mean duration of long-term use was 11 +/- 7 months. On long-term follow-up, 12 (67%) patients noticed some or dramatic improvement, while 6 (33%) experienced worsening or no change in symptoms (P = 0.16). Correlation (0.7) between short- and long-term response was significant (P < 0.005). Of the 3 patients with poor short-term response, none did well long term. Of the 11 patients with some or dramatic response in short-term, 7 continued to have some response long term. There was no relation between gastric emptying time and response to erythromycin suspension. Conclusions: Treatment of gastroparesis with low-dose erythromycin and low-bulk diet results in a dramatic short-term improvement in the majority of patients. Short-term response predicts long-term response. This response may not be as great, possibly due to tachyphylaxis.