The present invention provides an apparatus for instilling fluid into a patient having an intestinal stoma so as to administer an antegrade colonic enema. The portable instillation apparatus comprising in combination: a fluid reservoir, a pump assembly, a control module, a fluid delivery tube and an intestinal stoma catheter wherein the control module is operable to automatically deliver a predetermined volume of instillation fluid at a specific flow rate and pressure range suitable for a particular patient. The portable instillation apparatus utilities a gear pump manifold and a robust empty reservoir detection mechanism, facilitating the portability, durability and reliability of the apparatus over-coming the disadvantages of traditional peristaltic pump mechanisms. The portable instillation apparatus maximizes the ease of transport and use of the device while also enabling a method for a patient to self-administer an antegrade colonic enema within a short time period and without intervention.
