Goals: To evaluate the need for on-demand treatment with proton pump inhibito r in patients with endoscopy-negative GERD.Background: Studies indicate that on -demand therapy is suitable for patients without mucosal disease, but the need for PPI in a monotherapy situation is not known. Study: Forty-one patients with heartburn and/or acid reflux of more than 3 months duration participated in the study. All were endoscopy-negative and had responded positive to a test with l ansoprazole 60 mg ×1 for 7 days. Twenty-four hour pH monitoring was attempted in all, but failed in 4. Twenty-eight had pH< 4 more than 4%of the time, 9 had less. During a 3-month period, the patients were allowed to take 1 capsule 30 mg lansoprazole on-demand, maximum 2 capsules a day. The remaining capsules wer e counted monthly. Results: In the 3-month period, the median mean daily consum ption was 1.06 capsule (95%CI: 0.72-1.09). No significant difference was found between those with normal or abnormal 24-hour pH-metry. Sixty-three percent used 6 or more capsules a week. Conclusion: Patients with longstanding negative -endoscopy reflux disease, whether abnormal or normal 24-hour pH-metry, have symptoms that demand effective therapy. Using PPI on-demand as monotherapy, mos t patients will need 1 capsule per day. Goals: To evaluate the need for on-demand treatment with proton pump inhibito r in patients with endoscopy-negative GERD. Background: Studies indicate that on-demand therapy is suitable for patients without mucosal disease, but the need for PPI in a monotherapy situation All were endoscopy-negative and had responded positive to a test with l ansoprazole 60 mg x 1 for 7 days Twenty-four hour pH monitoring was attempted in all, but failed in 4. Twenty-eight had pH <4 more than 4% of the time, 9 had less. During a 3-month period, the patients were allowed to take 1 Capsules 30 mg lansoprazole on-demand, maximum 2 capsules a day. The remaining capsules wer e counted monthly. Results: In the 3-month period, the median mean daily consumtion was 1.06 capsule (95% CI: 0.72-1.09). No significant difference was found between those with normal or abnormal 24-hour pH- Sixty-three percent used 6 or more capsules a week. Conclusion: Patients with longstanding negative-endoscopy reflux disease, whether abnormal or normal 24-hour pH-metry, have symptoms that demand effective therapy. Using PPI on-demand as monotherapy , mos t patients will need 1 capsule per day.