The mother of a teenage girl with mental health needs has complained about the “shocking” use of restraint at a hospital where 20 members of staff were suspended this month.

Kelly Wilthew says her daughter was lifted from her bed by her wrists and ankles and slammed on the floor while at West Lane hospital in Middlesbrough, leaving her in agonising pain.

“She was screaming saying she was hurt and she was bleeding … I knew it was wrong but we were completely helpless,” she said.

Wilthew says her then 17-year-old daughter, Faith, should not have been restrained on her front due to a hole in her stomach caused by a stoma, the result of an operation to deal with a tumour. Restraining individuals with a stoma can lead to significant and even life-threatening complications.

After a review of restraint techniques, staff were given a beanbag to reduce the impact of restraint on Wilthew’s spine and stomach. This advice was only temporarily followed, say Wilthew and her daughter.

Faith Wilthew, now 18, said the experience left her feeling like she was nothing.

“They kind of treated me like an animal. They would just lift and move me whatever way they wanted to. They definitely did not listen to me,” she said.

Her mother claims inexperienced agency staff were brought in to plug gaps at the Middlesbrough hospital, who were ill-equipped to deal with her daughter’s needs.

On one occasion, Wilthew says an agency staff worker ran out screaming when her daughter was found with a ligature around her neck, despite being in a unit for young people with mental health needs.

On another occasion in December 2017, a letter seen by the Guardian shows that Wilthew complained to managers that staff had left her daughter with a broken arm overnight.

She describes the experience as having been a “living nightmare”.

“I won’t sugarcoat it, it was horrendous. It destroyed the whole family and we’re only starting to pick up the pieces now,” said Wilthew.

Responding to the claims, Elizabeth Moody, the director of nursing and governance at Tees, Esk and Wear Valleys NHS foundation trust, said: “We are aware that Faith’s family were unhappy with the care and treatment she received while she was an inpatient at West Lane hospital.

“At the time we worked with them to try and resolve the issues … We are sorry that they still feel unhappy about her experience on the ward.”

The family were unsurprised by reports that 20 staff have been suspended. Concerns date back as far as 2013, when an investigation took place in response to concerns around safety. No significant issues were raised in the report.

A subsequent inspection in June 2018 raised concerns over increasing use of restraint on Newberry ward, where Wilthew was a patient, and on the Westwood ward. The report raised concerns over low staffing levels and inadequate safety at the hospital.

The Tees, Esk and Wear Valleys Trust has published a statement confirming that concerns over non-approved techniques were being used to move patients had led to the suspensions, adding: “Concerns were raised that some procedures and guidelines were not being followed correctly. Our patients are our priority and we responded quickly to these concerns. We are currently carrying out a full and thorough investigation.”

Additional staff have been temporarily assigned to the ward while the investigation takes place, a measure the trust said aimed to “ensure a safe level of staffing across all wards at West Lane hospital”.

Wilthew did not find the statement reassuring: “That’s what they said [when I raised complaints about Faith] two years ago. Clearly nothing has changed.”

The family are hopeful that increased scrutiny will lead to change for other young people in the hospital: “I feel relieved to think that if there’s so much emphasis on the wards and the stories then maybe it will make them clean up their act.”