My dad can hardly walk around the shops without complaining that bottom and/or knees hurt. also, been going toilet every 5 minutes. pee all over house?

Exam needed: Your father will need to see his DR, get a exam done to address these concerns.

Neuropathy, diabetes: this could be neuropathy, this could be diabetes, you could have a prostate problem, he could have a urine infection, you could have arthritis, this needs to be evaluated by his physician to help clarify what the symptoms are and get him some relief