Prostatitis :: Feeling Of Fullness Or Tension In My Rectum?

I've been having some symptoms for years now that have a big affect on my quality of life and hold me back quite a lot, and I'm starting to think I might have prostatitis.

The main symptom that annoys me is a feeling of fullness or tension in my rectum. In the past, it got so bad I could not sleep and it drove me up the walls, I felt like I had to defecate but I didn't. I would wake up feeling fine, but as the day went on, the tension would build and build and it got really noticeable by the evening. I still get this but have learned to manage it better as I will explain below. I also have Irritable Bowel Syndrome, but my bowel movements are in fact very regular - the only IBS issue I have is spasms that were noted during a sigmoidoscopy. On a related note, I would also get very painful proctalgia fulgax spasms that wake me up suddenly at nigh and last for maybe 10 minutes or so. If I do not get a good rest every night, I wake up with the tension and pain the next morning and it makes for an unpleasant day.

Certain things would really aggravate the sense of rectal fullness/tension. Sitting is the worst culprit, if I sit on a hard seat I will have nasty feelings of pain and tension in my rectal area for days. If I have a bowel movement that does not go completely smoothly, I get a feeling of incomplete evacuation and will get feelings of tension and spasming for the rest of the day. I also tend to feel quite sensitive after a bowel movement and avoid sitting down at all for maybe an hour afterwards or else I will cause this tension/fullness feeling. Because of these problems I am paranoid about keeping a regular diet so my bowel movements are regular and smooth. I eat the exact same thing every day, and in particular avoid alcohol since it causes harder movements and wrecks the next day.

In the past, I thought my problems might be caused by internal haemorrhoids, but a sigmoidoscopy showed that everything looked fine (only very minor haemorrhoid inflammation), but the doctor did note some spasms/hypersensitivity in the rectal area caused by the movement of the scope. I then thought it might be levator ani syndrome. However, I more recently stumbled across chronic prostatitis online, and I realised I had many of those symptoms that I did not think of as problems. For example, I get up 2-3 times each night to urinate, I get random pains in my left testicle or the tip of my penis, etc.

The control measures I have learned that work for me over the years are also consistent for chronic prostatitis. I take a hot sitz bath every night now (with the weight on my hands) and that is a huge help in relieving the feelings of tightness/fullness. This also stopped the proctalgia fulgax spasms I would get at night. If I am not at work, I avoid sitting completely and this has also helped prevent the tension/fullness feeling from building throughout the day.
In summary:

Considering that my main symptoms are rectal pain/tightness/sense of fullness/spasms, and that these are accompanied by frequent urination at night and occasional, random genital pain, would all this indicate that chronic prostatitis is my problem?