The ability to record high-quality electrophysiology data from the gastrointestinal tract and enteric nervous system is of use in understanding a variety of disorders and improving healthcare via early diagnosis. However, such measurements remain challenging because electrodes must be implanted surgically or worn on the skin, which results in a trade-off between signal quality and invasiveness. Here we report an ingestible device for gastric electrophysiology. The non-invasive system, which is termed multimodal electrophysiology via ingestible, gastric, untethered tracking (MiGUT), consists of encapsulated electronics and a sensing electrode ribbon that unrolls in the stomach following delivery to make contact with the mucosa. The device then records and wirelessly transmits biopotential signals to an external receiver. We show that the device can record electrical signals—including the gastric slow wave, respiration signal and heart signal—in a large animal model and can monitor slow wave activity in freely moving and feeding animals.