male cat grooming...should I be worried?

My little guy has been recovering from crystals and some blockage.
He had a catheter, and has been recovering since last Tuesday.
He is doing much better, acting normally, and peeing good amounts.

I have a small concern...
Every now & then I see him grooming himself as he has been, ever since he got home and he tends to get very involved in it. Then I notice his little penis poking out. He hasn't been overly licking it, like prior to his blockage.
And as I said he has been going a normal pee amount.

Is this normal? As far as post-catheter goes?

The vet said that this is normal, as he has had some "trauma" down there and would be consoling himself....

What are other's experience?

Does he sit down to lick himself as soon as he's out of the litter box? That's one important sign of irritation.
Even if you don't see this, licking is always a sign kitty is trying to deal with pain, irritation, burning sensation.

I would urge you to ask your vet for a short course of anti-inflammatory medication (prednisone) to make him feel more comfortable and to help with the healing process.
(In these situations prednisone has always worked well for us, so I can recommend a short course without reservations.)