Devices and methods can be used for the endoscopic treatment of conditions such as obesity and metabolic diseases. For example, this document provides devices and methods for bypassing portions of the gastrointestinal tract to reduce nutritional uptake. The devices provided herein can be endoscopically implanted such that direct visualization of the entire implant location within the gastrointestinal tract is attained. In some embodiments, the device is distally deployed utilizing a technique that is like that of single or double-balloon enteroscopy.