Cat anal gland problem?

One of my cats seems to squirt from his anal glands a lot, spontaneously for no apparent reason and sometimes on to people or bedding, which is really gross because of how bad it smells even though it's such a small amount. Hr actually got me directly last time because I was in bed and petting him right before it happened. I had to go take a shower at 2 am to wash my hair.

There doesn't seem to be any stress cause for this as he just does it randomly, usually he is moving or stretching, and then the glands express suddenly. I asked my vet if there might be a problem and she said usually the fluid isn't clear like I described and they don't just squirt randomly like that. She checked him over and said there wasn't any noticeable issue. However he keeps doing it, probably once every few weeks or so, and I'm not sure what to do.

Are you sure it is his anal gland and he is not spraying? I have never heard of clear fluid coming out of anal glands before so that is why I ask. I just did a google search and apparently clear fluid is secreted to mark territory when scared.

Did the vet try to express his anal glands and were they at all impacted? I would get a second opinion. 

If this is not a medical issue and he is doing this to mark his territory you may want to try feliway and sprit essences (http://store.jacksongalaxy.com/category-s/1849.htm)

I don't think he's spraying. He's been neutered since he was 10 weeks old and has never sprayed before, plus it's only a small amount of stuff that comes out and it smells really bad like anal gland fluid, not urine. Also he does not seem to be aware that he is doing it. It happens randomly and there aren't any behavior cues before he does it, he doesn't seem to notice it's happening. It's not when he's scared or anything either which is why I thought there might be a problem.

Then yes I would take him to another vet to have them take a look at his anal glands he may have an infection.