An embarrassing, "sh**ty problem

I know it’s an uncomfortable subject but I think you need to mention it.
Perhaps ask if he’s suffering from piles or diarrhoea and whether you can get anything to help ... such as cream or medication. Then you could ask again if he needs anything to help ... should you notice it again.

My partner never used the moist wipes, he just assumed they were mine for indeterminate uses. When I explained what they were for and he tried them, he found them useful and comfortable.

I think a gentle conversation....

Reading recent comments perhaps you do need to talk to him.

He might have a medicsl problem that actually causes him to 'leak'. If so, he might also also be too embarrassed to mention it or see a doctor. Do try to gently raise the subject with him, in case it's something like that.

I'd shame him and tell him there's more skid marks in his underwear than at Brands Hatch.

Could he have piles Nan2six? They can make proper cleaning more difficult. If this is a recent problem there may be a medical reason for it.

Next time he gets off the sofa and you notice a whiff ask him if he's stepped in something and continue in that vein till he takes the hint, said often enough he'd be really dense not to catch on.

To be honest , I would just tell him. Better be embarrassed by you than have friends putting up with his smell.

I like missingmoominsmama's idea. Least embarrassing, but gets to the point.

Read, and perhaps join, the BAM group of facebook. Its a closed group so you won't be able to read the posts unless you join - but it's very helpful.
BAM stands for bile acid malabsorption and you can look it up on google.
Would a small tin of Vaseline be helpful (I mean would he use it? surely it must be uncomfortable? My DH ignores moist sheets too.
He also won't discuss these things and gets furious if I mention anything like that. Years ago I noticed one of his crown jewels was swelling, and he went into a dark sulk for days about me interfering in things I knew nothing about.
Three years later he had to have it removed.
The temptation to say 'I told you so' was almost irresistible.

I would just say ‘you smell of poo’ next time he stands up and you get a whiff.

Does he leave marks in his underwear? He must know he has a problem if he does.

Walk past the loo door when he’s in and shout, ‘I hope you’re wiping properly!’ in a jokey tone. He’ll know you’ve noticed, and you don’t have to say anything directly to him.

Hi Nan2six - can't suggest how to tackle DH re the unpleasant aroma, but PLEASE don't use those moist wipes in your loo. I know that they are supposed to dissolve in water like loo paper, but they don't, and can cause untold problems in the sewers.

I've worked for a water company for many years, and the slogan is - pee, poo, paper - (down the toilet that is)