Endoluminal Functional Lumen Imaging Probe (EndoFLIP©) is a novel technology, originally used to measure the dimensions and function of a hollow organ. The proposed study intends to use a modified EndoFLIP to integrate several technologies into one which will save time and reduce test variability. A major difference from previous EndoFLIP studies are that the device will be defecated rather than providing static data from one location in the anal canal.