OBJECTIVE To study extensively the therapeutic approach of gastroesophageal reflux disease in intellectually disabled children. METHODS We studied the effect of omeprazole sodium on healing and symptom relief in 52 institutionalized intellectually disabled children (male-female, 21:31; mean age, 15.4 years; range, 4-19 years). METHODS Endoscopically proven esophagitis (grades I-IV, Savary-Miller classification) was treated with omeprazole sodium, 40 mg/d (20 mg/d for children weighing <20 kg) as healing dose for 3 months, and 20 mg/d (10 mg/d for children weighing <20 kg) as maintenance dose for another 3 months. After 3 and 6 months, results of treatment were evaluated using symptom scoring and/or endoscopy. For patients with relapse, the dose was increased. RESULTS At first endoscopy, 19 patients (36%) of 52 showed grade I esophagitis; 20 (38%), grade II; 6 (12%), grade III; and 7 (13%), grade IV. In 44 (86%) of 51 patients, treatment was effective in healing esophagitis and keeping patients in remission, independent of the severity of esophagitis. In 7 patients (14%), a symptomatic relapse was observed after decreasing the dose. However, these patients became symptom free again after increasing the dose and showed healing on endoscopy at the end of the study. One child did not finish the study for reasons not related to therapy. Marked improvement of persistent vomiting, regurgitation, food refusal, iron deficiency anemia, and signs of depression was seen at the end. CONCLUSIONS Omeprazole is highly effective for all grades of esophagitis in intellectually disabled children, without adverse effects. The dose needed to maintain the remission can be titrated according to the reflux symptoms. One disadvantage of medical therapy is that it is open ended, in contrast to operation, but surgery in this population has high mortality and complication rates.