There are concerns a rationing of incontinence aids is forcing veterans in aged-care facilities to sit in their own filth.

Partners of Veterans Australia has conducted case studies of aged-care facilities in the Hunter Valley and Lismore in New South Wales, and in Queensland over the past year.

Spokeswoman Gail McDonnell says the studies found inadequate nursing care and rationing of essential items such as mobility and incontinence aids.

"Countless people ring me and say they just buy the extra incontinence aids themselves so their mother doesn't have to be so embarrassed," she said.

"Because they get full, they get smelly, and they're too embarrassed to come out of their room."

Ms McDonnell says it is an Australia-wide problem, with high-care patients the worst affected.

She says the Department of Veteran Affairs provides inadequate incentives for aged care facilities to offer the required services.

DVA says funding is provided for appropriate care and any allegations will be investigated.