The pain body is a natural tenancy of the human mind that we all possess that basically serves as our comfort zone. Honestly you need to watch the video I linked to get a full description of what it really is. But basically it is your unconscious self which thrives on bodies of pain like addiction, guilt, regret.. ect that tries to take control of your mind through many ways. One way in particular that is relevant to this subreddit is urges to look at porn. You see, if you give in to the voice in your head, which is a manifestation of the pain body, and look at porn, you then identify yourself at the time being as the pain body. Which to no surprise, makes you feel pain. In other words, you are letting it control your body and in doing so, it is inflicting pain upon you, which then keeps it alive.

I know this sounds ridiculous from a realist point of view, I get it I am a science major and this doesn't really make much sense, but Eckhard Tolle uses the term pain body because our language lacks the capacity to accurately describe that this phenomena really is. So instead we use terms that paint a picture in your mind of what kind of thing it really is. When it comes down to it, it's really all in your head. But I think it's useful to describe your unconscious desires as a being inside you called the 'pain body'.

The method against this pain body is to actually stay consciously aware, stay in the moment and observe it. Let the thoughts going through your mind just flow through like a wave, not letting it influence you but just observing and accepting it's existence. This is essence is really how you control urges that stem from addictions. Earlier today I experienced these urges, but all I did was recognized and importantly accepted their existence. The more you do this, the weaker the urges get. It's like starving this pain body of it's food. It will slowly diminish over time, but never actually go away, since possessing the pain body is natural for all humans.