I had my own surgery to repair a right inguinal hernia last Friday (July 20th). I had a standard incision with a piece of mesh installed to reinforce the muscle wall. My surgeon has competed in triathlons and is sensitive to biking issues.
I had my followup today (July 26th). Healing is progressing well--I'm right on schedule. In response to the question about returning to biking, his response was: go ahead and give it a try. Start with easy spinning and short routes. Build up to longer miles. You can't tear or harm anything, but if you're sore the next day, give it a rest.
I don't know if this advice extends to anyone else, but this is what he told me. I'll try a five mile trip tomorrow and move along from there.
Bob P.