Many people who are self-catheterizing for the first time worry about insertion. Fortunately, it’s very difficult to insert a catheter too far. If the catheter is inserted too deeply into the bladder, it will just coil up onto itself.
Some men may feel like they’re inserting their catheter too far because they’ve hit a muscle known as the external sphincter. Most of the time, this resistance can be overcome if the patient pushes or strains against the catheter tip. It may feel uncomfortable, but shouldn’t feel painful.