What Causes Vaginal Bleeding After Endometrial Ablation?

Hello there my 33yr old daughter had an endometrial ablation and the removal of her right fallopian tube 7 days ago. She has recently had bright red bleeding. Yesterday she returned to Emergency at the hospital where they did an ultrasound and blood tests for fever. Their conclusion is that all is well within the vagina and the bleeding is from the operation. Today she is experiencing heavier bleeding Dark red blood, then bright red again and has hardly slept from the pain. She has lost trust in the hospital. Any thoughts. Thanks from Sharon