Wireless endoscopy device is a miniature medical device that travels through the digestive system to collect images or physiological data and transfers them to an external console worn by patients or to a nearby TV/computer for display and monitoring. The current commercial devices have a dimension of approximately 11 x 26 mm with the shape of a pill so as to reach areas such as the small intestine to obtain video images. These devices record and transmit images over approximately an eight hour journey through the gastrointestinal (GI) tract. A video-based capsule device produces a large amount of data from high-resolution cameras, which is delivered over a high capacity wireless link. The commercially available capsules operate based on passive motion with no control over its position or orientation. These devices operate using small batteries with limited energy source. This article discusses implementation issues and presents details of techniques for design of wireless capsule systems. In addition, it outlines new studies involving motion control, localization and wireless energy transfer to increase the battery life of current wireless capsule devices. These new features will enable the next generation wireless capsule endoscopy devices to actively navigate within the GI tract of the human body and enable new therapeutic operations. Finally, the limitations of current devices are discussed and future directions and design challenges are highlighted for designers and researchers.