Thanks for your query.Your father who is 56 years old has grade two enlarged Prostate
.with minimal voiding symptoms.Since he does not have obstructive symptoms now he does not need any active intervention or medicines ,However enlarge prostate is a progressive pathology and progresses further with advanced age.So keep him under observation and moment he develops symptoms like increased frequency of micturition,nocturea.poor stream get his Ultrasound
scanning done and consult some Urologist
for evaluation. There is nothing to worry about it as Enlargement of Prostate is a ageing problem and not the disease to be worried about.