Abstract: A system for insufflating a body cavity comprising a swallowable capsule comprising a chamber (11) containing a fluid capable to generate biocompatible gas or vapour by phase transition or chemical reaction, the chamber (11) being formed with at least one orifice (7) for placing it in communication with the outside. The orifice (7) is blocked by a shutter (4, 6; 26) made of magnetic material and there are provided elastic means (8) able to generate an elastic force sufficient to keep said shutter sealingly engaged in the orifice. The system further comprises magnetic actuating means (12; 34) external to the body cavity for generating a magnetic force having strength sufficient to overcome the elastic force of the elastic means disengaging the shutter from the orifice.