PROBLEM TO BE SOLVED: To provide a gastrostoma assist tube and assist kit for exchanging a gastrostomy catheter capable of reducing a burden of an affected part when exchanging a gastrostomy catheter in an existing gastrostoma.SOLUTION: A gastrostoma assist tube 100 includes: a tube body 10 a guide wire lumen 11 formed in the tube body 10 for inserting a guide wire and a proximal opening 12 and a distal opening 13 as openings of the guide wire lumen 11. A cut part 14 formed by cutting a wall part 15 of the tube body 10 in the wall thickness direction is continuously or intermittently provided on the wall part 15 of the tube body 10 from the proximal opening 12 to the distal opening 13. When the gastrostomy catheter placed in the gastrostoma is exchanged, the cut part 14 is used for inserting a gastrostoma sheath 200 in the gastrostoma.
