Hallo - I am assuming your parents get some kind of benefits and therefore may be eligible for government help? They no longer provide crisis loans but the following may be of help:-
https://www.gov.uk/budgeting-loans
If your father has a social worker, they may be able to find out if you can get some kind of community grant or help from a charity.
Another option is to address the incontinence issue by getting your father appropriate continence products. He can have an assessment from a continence nurse by contacting the District Nurse service.
I think the best option is to start with Social Services. I hope you can get something sorted out.