A 70 uear old female presented to the ward with multiple episodes of diarrhoea and vomiting. The diarrhoea was watery in consistency. Her RFTS were deranged at the time. She was admitted as a cas eof acute gastroenteritis leading to Acute Kidney Injury.She was managed promptly. After 1 day her RFTS  got futher deranged urea was 99 and creatinine 5.
She also developed periorbital puffiness.
She has no history of Hypertension or diabetes. On examining agaib her bp was 150/60 mmhg. What can be the cause?