Minature, wireless battery powered endoscopic capsules need to be able to diagnose the enture human digestive tract. This paper describes an analog-digital mixed-mode low power IC design that fits inside a bi-directional miniaturized capsule. The system on a chip includes an image capture module, digital signal processing and a control module with image compression, static random access memory and a wireless transceiver module. The low power design of the digital circuits reduces the capsule power consumption by 36% compared to conventional designs. The digital circuits and capsule power management algorithm have been tested using field programmable gate arrays. The main specifications of the analog ray frequency circuits have been verified in simulations. The analog-digital mixed-mode chip has been taped out using 0.18μm CMOS.