Is It Safe To Soak In The Tub After Having Vaginal Hysterectomy?

My daughter had a vaginal hysrerectomy on Monday this week; she has not beem able to urinate without a catheter. She was sent home Friday morning now, with another catheter and told to soak in the tub to relieve the pain in her back!. Isn't that just the wrong thing to do? She is 39, 165 lbs. usually in perfect health! Thanks