Hi, many thanks for the query!
Diastolic BP of 55 as you said is not good, ask him to drink more water.
If BP doesn't come up, see your doctor.
Blood in urine can be due to several causes, more commonly it is due to Ca-oxalate
stones causing mechanical trauma to mucosa of urinary tract
as it has spikes on its surface.
Also do- RFT, CBC.
So, for time being, you may take anti-spasmodics, pain killers, diuretics with
your doctor's opinion.
Wish you a good health.