A capsule endoscope (120, 122), comprising: a sensor system (110, 112, 210) comprising a light source, an image sensor for capturing image frames of a scene illuminated by the light source; a housing to enclose the sensor system (110, 112, 210); and at least one pouch (140, 150, 220, 320) containing an effervescent, the pouch (140, 150, 220, 320) being attached to the housing, wherein the pouch (140, 150, 220, 320) is encapsulated within a dissolvable shell, dome or coating (131, 223), and specific gravity of the capsule endoscope (120, 122) is greater than 1 when the pouch (140, 150, 220, 320) is encapsulated within the dissolvable shell, dome or coating (131, 223); wherein the capsule endoscope (120, 122) is configured to control estimated inflation and deflation periods of the pouch (140, 150, 220, 320) such that the capsule endoscope (120, 122) has the specific gravity greater than 1 for a first period of time, less than 1 for a second period of time following the first period of time; wherein the capsule endoscope (120, 122) is adapted for being swallowed; characterized in that the capsule endoscope (120, 122) has the specific gravity greater than 1 again for a third period of time following the second period of time; and that the capsule endoscope (120, 122) is configured to control estimated inflation and deflation of the capsule endoscope (120, 122) according to parameters selected from a parameter group comprising a combination of pouch material and pouch wall thickness to affect a rate of diffusion of body liquid and gas into or out of the pouch (140, 150, 220, 320); wherein the pouch material comprises polyetherblockamide copolymers, thermoplastic polyurethanes, polyamides, polyamide block copolymers, polyamide elastomers, polyurethanes, polyesters, polyester copolymers, polyamide copolymers, polyurethane copolymers, polyether copolymers, polyesteramides, polyesteramide copolymers, polyvinyl chloride, polyvinyl chloride copolymers, polyvinylidene dichloride, polyvinylidene dichloride copolymers, fluoropolymers, polyvinyl fluoride, polyvinyl fluoride copolymers, polyvinylidene difluoride, polyvinylidene difluoride copolymers, polyvinylpyrrolidone copolymers, polyvinylalcohol copolymers, or a combination thereof; and wherein the pouch wall thickness is between 0.00508 mm to 0.254 mm. a sensor system (110, 112, 210) comprising a light source, an image sensor for capturing image frames of a scene illuminated by the light source; a housing to enclose the sensor system (110, 112, 210); and at least one pouch (140, 150, 220, 320) containing an effervescent, the pouch (140, 150, 220, 320) being attached to the housing, wherein the pouch (140, 150, 220, 320) is encapsulated within a dissolvable shell, dome or coating (131, 223), and specific gravity of the capsule endoscope (120, 122) is greater than 1 when the pouch (140, 150, 220, 320) is encapsulated within the dissolvable shell, dome or coating (131, 223); wherein the capsule endoscope (120, 122) is configured to control estimated inflation and deflation periods of the pouch (140, 150, 220, 320) such that the capsule endoscope (120, 122) has the specific gravity greater than 1 for a first period of time, less than 1 for a second period of time following the first period of time; wherein the capsule endoscope (120, 122) is adapted for being swallowed; characterized in that the capsule endoscope (120, 122) has the specific gravity greater than 1 again for a third period of time following the second period of time; and that the capsule endoscope (120, 122) is configured to control estimated inflation and deflation of the capsule endoscope (120, 122) according to parameters selected from a parameter group comprising a combination of pouch material and pouch wall thickness to affect a rate of diffusion of body liquid and gas into or out of the pouch (140, 150, 220, 320); wherein the pouch material comprises polyetherblockamide copolymers, thermoplastic polyurethanes, polyamides, polyamide block copolymers, polyamide elastomers, polyurethanes, polyesters, polyester copolymers, polyamide copolymers, polyurethane copolymers, polyether copolymers, polyesteramides, polyesteramide copolymers, polyvinyl chloride, polyvinyl chloride copolymers, polyvinylidene dichloride, polyvinylidene dichloride copolymers, fluoropolymers, polyvinyl fluoride, polyvinyl fluoride copolymers, polyvinylidene difluoride, polyvinylidene difluoride copolymers, polyvinylpyrrolidone copolymers, polyvinylalcohol copolymers, or a combination thereof; and wherein the pouch wall thickness is between 0.00508 mm to 0.254 mm.