Introduction: Intragastric balloons (IGB) are a safe and effective endoscopic weight loss procedure that has recently been approved for use in the U.S. The Manhattan VA initiated the first bariatric endoscopy program in the country, which works in conjunction with the MOVE! program. We report an interesting case of an obese man with dramatic weight loss and obstructive symptoms after IGB. Case report: Patient is a 45-year-old veteran with BMI of 38 kg/m2, hypertension, and obstructive sleep apnea, who presented for IGB. Physical exam and labs were unremarkable, with initial weight of 233 lbs. An Orbera IGB (Apollo Endosurgery, Austin, TX) was implanted and filled with 650 mL of saline mixed with methylene blue. At 4 months after implantation, the patient had lost an impressive 46 lbs, with active participation in the MOVE! program. At 4 months, he presented with new-onset nausea and vomiting. He denied abdominal pain, or changes in color of stool and urine. Initial abdominal x-ray(AXR) was unremarkable (Fig. 2a). The patient improved temporarily with dietary changes and anti-emetics, but vomiting after solid meals resumed and he was admitted. On admission, his weight was 169 lbs, with K of 3.1 mEq/L, BUN 32, creatinine of 2.0, normal liver tests and lipase. Hyperinflation of balloon, small bowel obstruction, gastric ulceration and gastroparesis were considered. Repeat AXR showed air-fluid levels (Fig. 2b). Upper endoscopy revealed intact freely movable IGB, located in antrum. IGB was removed, and the patient's symptoms resolved. Four months later, the patient has maintained the weight loss, with weight of 174 lbs (BMI 27 kg/m2) and a total excess weight loss of 68%.Figure: Abdominal x-rays 4 months after IGB placement revealed intact balloon (arrows) with no deflation or migration. Fig. 2b. Air-fluid level on hospital admission, 5 months after balloon implantation.Discussion: We present a patient with BMI of 38 kg/m2 status post IGB therapy with 59-lb total weight loss, later complicated by persistent gastric outlet obstructive symptoms with no evidence of mechanical obstruction.This functional dynamic gastric outlet obstruction may be attributed to the patient's sudden weight loss, especially since typical rate of weight loss after IGB is lower. The patient had no diabetes history, underlying infiltrative process, or medications use that could explain the functional gastroparesis. This study highlights an unexpected phenomenon that physicians should be aware of when monitoring effects of acute weight loss and consider in the presentation of late nausea and vomiting (after 3 months of implantation) in patients with IGB.Figure: Image of endoscopic intragastric balloon placed in gastric fundus and inflated with 650 mL of saline.Figure: BMI trend over 9 months, including time of IGB placement, hospitalization with IGB removal, and four-month follow-up after extraction.