There are two reasons why a person cannot pass urine after prostate surgery.
One is residual prostate which is still causing the block or obstruction.
Second reason is a weak bladder
which lacks the power to pump the urine out. Your symptoms suggest that you may have a weak bladder.
If it had been a residual prostate,the bladder would be normal and you will have the normal urge to void once the catheter is removed. And once the bladder is full it is very painful even when you are not trying to pass urine.
But a weak bladder does not create an urge nor cause pain at rest. Sometimes it could be a mix of both the features.
The reason for this condition is usually long standing prostate block against which the bladder had been working on; ultimately resulting in its failure and weakness.So resting the bladder is the best treatment it.
Other causes could be diabetes, spine problems, previous pelvic surgeries( not the LASER one).Old age can contribute to this problem too.
The only way to diagnose this condition and to know whether the bladder is weak is to do an Urodynamic study.As it has been 3 months post surgery, you are an ideal candidate for this procedure.
This study involves filling the bladder with water and then measuring the bladder pressures with fine tubes through the urethra
. If enough pressure is not generated then it means there is weakness in the bladder muscles.
There is no specific treatment for this condition than waiting it out till it improves of its own.Sometimes improvements have been noted up to 1 year after acquiring this condition.Till that time bladder has to be kept empty either by an indwelling catheter or intermittent catheterization( tube is put every 4- 6 hours).
The only medication which has been useful for this condition is bethenacol. But results are not overwhelming with this drug.
I would advise you to discuss the option of Urodynamic study with your doctor and come to a diagnosis as soon as possible and then work towards the management.
I hope this helps you understand your problem in a little better way than before.
If you have any doubts, please let me know.