An expandable intragastric balloon (1) to be implanted in, and subsequently removed from, the stomach (2) of a patient through natural orifices as part of a treatment for obesity. The intragastric balloon (1) includes an outer casing (3) sufficiently flexible that the outer casing can change from a first configuration, the introduction configuration, to a second configuration, the deployed configuration, in which the balloon adopts a functional shape. The balloon (1) includes means for configuring the balloon in an extraction configuration (10), the means exerting a stress on the intragastric balloon (1) such that the balloon changes from the deployed configuration to a third noticeably-smaller contracted volume configuration, the extraction configuration, by acting on the outer casing (3) such that the casing (3) essentially returns to or towards a predetermined shape corresponding to the extraction configuration.