Abstract: Systems, devices and methods for performing medical procedures in the intestine of a patient are provided. A medical device for performing a treatment and/or a diagnostic procedure can include an elongate shaft assembly comprising at least a shaft assembly first section comprising a distal section of the shaft assembly, and a shaft assembly second section proximal to the first section, and a functional assembly positioned on the shaft assembly first section. Additional sections of the shaft assembly can be included, and each section can comprise a different construction, such as to achieve a different stiffness as described herein. Variable stiffness along the length of the shaft assembly can be provided to aid in translation of the device through the patient's GI tract (e.g. through the stomach and into the small intestine), as described herein.

Abstract: A system for ablating surface tissue of a patient is provided. The system includes a console and an ablation catheter fluidly attached to the console. The console includes an ablative fluid supply, a neutralizing fluid supply, an injectate fluid supply, a pump assembly, and a vacuum supply. The ablation catheter includes an expandable functional assembly, a tissue expansion subsystem for expanding sub-surface tissue in the intestine of the patient, and a tissue ablation subsystem for ablating surface tissue in the intestine of the patient. Methods of ablating surface tissue are also provided.