What percentage of time/how common is it to get a 2nd uterine polyp or for 1 2 grow back after removal of a polyp? Ave length of time this happens?

Hard ? Uterine polyps are not that common to begin with. I am not sure what procedure was performed to remove them. If that was a d&c, then the polyp or polyps got removed entirely and it should not regrow quickly unless it is cancerous. If it regrew and the biopsy was not cancer, then it could have been that it was not removed in the first place. Anyway, we need more details on that.