Endoscopic devices and methods for imaging and treating organs and tissues are described. The endoscopic devices described herein include flexible endoscopes, rigid endoscopes, and capsule endoscopes. The endoscopic device may comprise one or more cameras and one or more light sources. In some embodiments, the endoscopic device comprises at least one white light camera, at least one blue light camera, at least one white light source, and at least one blue light source. In some embodiments, fluorescent targeting constructs can be injected into the subject and bound to and/or taken up by a tumor or diseased tissue. Diseased tissue can be identified by viewing the fluorescence emanating from the fluorescent targeting constructs by illuminating an in vivo body part of the subject with light having at least one excitation wavelength in the range from 400 nm to about 510 nm.