In one aspect, wireless gastrointestinal stimulations are described herein. In some embodiments, a system described herein comprises at least one transmitter and at least one stimulation device. The transmitter can include a signal generator operable to generate an electromagnetic signal, a first antenna operable to broadcast the electromagnetic signal, and an energy source. The at least one stimulation device is operable to deliver a pattern of electrical pulses to a gastrointestinal tissue comprising a muscle, and the stimulation device includes a circuit board having a circumference, at least one second antenna wrapped around the circumference of the circuit board, the at least one second antenna being configured to receive the electromagnetic signal and to generate an electrical current from the electromagnetic signal, and at least one electrode operable to deliver the electrical current to the muscle.