Methods and devices for providing information useful in the diagnosis of abnormalities of the gastrointestinal tract

An ingestible device useful for providing information useful for diagnosis of gastrointestinal abnormalities, comprising:

• a) an ingestible casing having a device axis, a body section, a distal end and a proximal end;
• b) inside said casing, an illuminator configured to project light radially outwards through an illuminator window of said housing;
• and
• c) inside said casing, at least one light-detection assembly configured to determine intensity of at least one specified wavelength of light projected by said illuminator and passing through an associated detector window after reflection from a portion of a gastrointestinal tract without acquiring an image.

A diffraction grating, comprising:

• a substantially conical-section surface having an axis;
• and
• on said surface, periodic features
• wherein said surface and said features are configured to reflect light impinging on said surface substantially perpendicularly to said axis at a wavelength-dependent angle in a general direction of said axis so that the diffraction grating functions as an optically dispersive element.

A method for providing information useful for diagnosis of gastrointestinal abnormalities, comprising:

• a) illuminating an area of an in vivo gastrointestinal tract of a living mammal with light, wherein said illuminating is outwards from inside the gastrointestinal tract lumen;
• b) without acquiring an image of said area, determining an intensity of at least one said specified wavelength of said light after said light is reflected from said area of said gastrointestinal tract;
• and
• c) providing information related to said determined intensity of said at least one specified wavelength of light indicative of a potential gastrointestinal abnormality in said area.