Very sorry to say that your father seems to have DIABETES NEPHROPATHY, that is damage to Kidney because of Diabetes. This is suggested by increased values of Blood Urea and Serum Creatinine
. For that you have to consult a Nephrologist
If the Nephrologist and the Anaesthetic agree then Gall Bladder can be removed by Laproscopic Cholecystectomy
, i.e. removal of Gall Bladder by Laproscopic Technique.
Also Alfa-blockers can be started for Hypertension
and Prostate Enlargement.
He can reduce his weight to help his Kidneys.