A prison wing for low-risk inmates has been described by inspectors as the "worst establishment we have inspected in many years" following an unannounced visit.
The category D side of HMP Lindholme, near Doncaster in South Yorkshire, had been "forgotten and neglected" after funding lost when the wing was returned to the prison service in January 2012 was not replaced.
Among its findings, HM Inspectorate of Prisons (HMIP) said there were religious tensions on the wing and discovered someone had defecated in washing facilities for Muslim prayers.
Described as an "astonishing situation" by the inspectors, more than a third of prisoners interviewed had felt unsafe at some time while drugs and alcohol were widely available on the wing, which was shut down shortly after the inspection.
There were also significant problems in other parts of the 1,000-capacity jail, which is one of a group of prisons in South Yorkshire set to be handed over to the private sector, the inspectorate said.
Chief Inspector of Prisons Nick Hardwick said: "The closure of the D side has reduced the immediate risks but legitimate prisoner grievances, the lack of activity, mixed staff-prisoner relationships and indications of some religious tensions, combined with the ready availability of drugs and alcohol, are an unhealthy mix.
"The uncertainty created by the prison's move to the private sector cannot be allowed to delay the urgent improvements that are required."
In the category C side of the jail, the inspectorate found that the needs of prisoners with disabilities were ignored, including a "distressed" disabled inmate who was "constantly taunted" and bullied for payment if he had to ask for help.
Uncertainty created by the pending move to the private sector added to the difficulty in running the prison, HMIP said. However, it added that these difficulties "did not excuse the very poor findings of this inspection".
Elsewhere, inspectors were concerned to find that reception, first night and induction arrangements on the low-risk wing, which was an immigration removal centre until January 2012, were done with minimal effort.