My husband's problem was porn. And they could not even give him counsel in this simple yet evil practice.
It's not in all cases, but typically, it usually has to do with one not submitting or the other losing interest in sex.
This is one of the usual follies with marriage- the sexual flame becomes a mere spark, or in some cases, the wife will 'punish' the husband by withholding sex.
It's something that needs to be paid good attention to, because couples will often put it off and it will start to become a problem- and by the time they realize it, they are already in the rut.
In most cases, unless the husband is just an obnoxiously sexual deviant, it is wrong to condemn him in the event he looks at pornography.
It usually means, simply, that there is a sexual issue that needs to be remedied.
I'll tell one way NOT to go about it:
A friend of mine's brother has been married for about a decade. They have two children, are religious, and the man is decent.
I never gathered the inner details, but I assume that in all probability there were intimacy issues between the two. They weren't getting along very well, that much I know. Nothing necessarily divorce-bound, but not very joyful nonetheless.
She eventually discovered pornography on his computer, and she outright got a separation in order.
And this went on for an entire year, and they are still 'working things out'. He felt obligated to take classes for porn addiction- it is not to such an extent, but he did for her.
And that's just outrageous. There have been several times where I have seen her and just wanted to give a piece of my mind, but one of my virtues is not to get involved in marital affairs so I've always just left it alone.