Abstract: A portable apparatus (51) for delivering a colonic lavage to a patient includes a portable frame (52) preferably constructed of tubing, a lavage liquid reservoir (71) and a waste reservoir (72) both stowable in the frame (52), a speculum (78) for delivering the lavage liquid to the interior of a colon and for receiving waste from the colon, a waste conduit (88) communicating at one end with the speculum (78) and at another end with the waste reservoir (72), and a first sphincter valve (87) selectively opening and closing the waste conduit (88). A pump (66) housed in the frame (52) delivers the lavage liquid from an interior cavity of the frame (52) to the speculum (78) via a delivery conduit (91) coupling the speculum (78) with a pump tube (102) communicating with the pump (66). A regulator valve assembly (58) communicates with the pump tube (102) and ensures that the lavage liquid is never delivered to the colon above a predetermined pressure.