Ah, a favourite question oldbooks.
I used to rely on prunes and dark chocolate and am still finding my way on LCHF. So far, the things that help include leafy green stuff (take a bow, spinach and broccoli), a couple of teaspoons of ground flaxseed (i pick up linwood's in the supermarket and just eat a teaspoonful or two with a glass of water). Loads of water, no, really, loads of water and then a single expresso after a relaxed meal.
When DH is home, he makes flaxseed and almond bread. I find it stalls me but one slice in an emergency.... Shout if you want the recipe, he got a bit obsessed a few weeks make and made loaf after loaf but has, i recollect, settled on his 'foolproof masterpiece' and has to stop himself from sulking when i stick to one slice, and even that occasionally. Hope you find what works for you.