A balloon catheter system includes a tube (30) and a dilator (10) detachable from the tube after the tube is inserted into a cavity in the patient. The cavity may be filled with gas or liquid to expand the viscera surrounding the cavity and the guidewire may be inserted using a trochar, for example. The tube includes one or more lumen to expandable balloons (38) that are inflatable by fluid inserted through the lumen (56) and into the balloon or balloons, which are formed by elastic film sealed on opposite ends to the external diameter of the tube. The dilator is held in place during insertion, such as by a stainless steel shaft and a sheath portion of the dilator extending over the end of the tube being inserted into the cavity. A portion of the sheath may extend over and protect the balloon. A retractor net may be used to capture and remove the dilator or the dilator may be designed as a bioabsorbable or digestible material or of a material that passes safely through the digestive tract of a patient.
