I want to know what is the disease.

My mother was initially diagnosed with Interstitial Nephritis. Gfr was 18 then. But for the next 4 years, Creatinine was 0.9- 2. Last year, in 2021, it suddenly increased to 10. There was no electrolyte disturbance, but she had anaemia from before. Her bp was 150/80 on average. Now, she is on dialysis, right after dialysis her creatinine stays 2.33, Bun 14, and with two days gap it increases to creatinine 4, Bun 30. But, there is not much edema, and her urine and electrolyte levels were normal before dialysis but now urine is less, 4 times a day and electrolytes sometimes changes. Doctors have never been honest to me, so is there any honest doctor who can answer this? Because everyone considers my mother to be old and they just rely on money. I am a truthful citizen and your help would be highly appreciated. Thanks