Nikki Gilbert, a 63-year-old woman from Farnham, was forced to use the makeshift changing room last Thursday.
She said: “Sterile surgical gowns in a toilet! It felt like a third world country.”
Ms Gilbert said the problem had been caused by one of two day-surgery units being converted into an overnight ward.
She added: “It was so busy that no beds were available to check many of us in, so the ‘overflow patients‘ had to sit in a waiting room.
“The surgeons, anaesthetists and nurses discussed our personal details with us in this room, where you could hear everything about the person across from you.
“Far worse was to come. We were then asked to change into surgical gowns in the toilet. Sterile surgical gowns in a toilet! It felt like a third world country. They have lost a lot of beds and the choice was to cancel urgent surgery – including cancer – or go ahead by using the toilet as a changing room.”
Ms Gilbert said the change had occurred only a few days before she went there last Thursday.
She felt the staff were doing their best but she also believed more thought could have gone into the arrangement.
She said: “Surely you should close off the toilet to people wanting to use it as a toilet, and sterilise it after every use, but they didn’t even do that.”
Ms Gilbert said a male patient near her in a waiting room where consultations took place was “very annoyed” about being asked to change in the toilet, and she felt there was a “lack of dignity” in that situation.
She continued: “At the point of putting on gowns the patients are still mobile so they could use a more suitable room a bit further away. They can’t keep going on like this. The nurses were apologising as it was complete chaos.”
A spokesperson for the Frimley Health Foundation Trust, which runs Frimley Park Hospital, said: “We are always sorry to hear if any patient feels they have not had the best possible experience at one of our hospitals.
“Over recent weeks our hospitals, like many others, have been working under extreme pressure. An increased demand for urgent and emergency care has meant we have had to open up extra areas for patients requiring an overnight stay.
“One of our day-surgery units at Frimley Park Hospital is part of our escalation plans for such extreme circumstances and unfortunately has had to be utilised as part of our response. This means we have made temporary changes to working practices and systems to make the best use of our resources and avoid cancelling as many patients who are awaiting surgery as possible. We know how important this is to those who may have been waiting a long time. All such changes are risk-assessed before being introduced.
“We obviously do have to balance the above with the overall patient experience and are looking into this feedback.
“We take all complaints very seriously, try to learn from them and see how we can improve the quality of our services, so we’d also like to remind all those who use our services that Frimley Park, like all NHS hospitals, has a patient advice and liaison service where issues can be raised confidentially either face-to-face, by phone or by email.”