<prompt> Answer this question truthfullyWhat is the medical condition known as Rubber Bleb Nevus Syndrome?  <response>: <reason> Blue rubber bleb nevus syndrome which is also known as BRBNS is a rare congenital vascular anomaly in which blood vessels do not develop normally especially in the gastrointestinal area. BRBNS shows characteristic blebs that are fluid-filled blisters as visible and well rounded lesions nevus. 