Ruby Hamilton, 75, was admitted to the new £545m hospital five weeks ago with heart failure.
Her family found her lying in wet, vomit-stained bedclothes, with a pool of urine under the bed.
The hospital said she was not left in that state long but has apologised for the delay in rectifying it.
'Not enough nurses'
Mrs Hamilton's daughter Christine said she was so upset by the lack of care given to her mother she had bought a hospital standard bed to move her into her own home in Sheldon, Birmingham, to care for her.
"They left her there in all that urine, we don't know how long she was there for but there was a pool of wee on the floor. It's disgusting.
"They spend all this money on this hospital yet still haven't got enough nurses to care for people."
She said she thought her mother had been given second class care by nursing staff because she was not expected to live.
Kay Fawcett, chief nurse at the Queen Elizabeth Hospital, said: "The hospital is concerned about the question of care delivered to patients at all stages of their illness.
"I am satisfied that the patient was not left for a long period of time in a wet bed and, as soon as the nurses were alerted, they took immediate steps to address the situation and to unreservedly apologise to the patient and the relatives."