It's the only problem I have with low-carbing, simply_h, and I understand your problem!
Proper live yoghurt, preferably organic, is good for your gut; add the flax seeds, and eat with stewed rhubarb sweetened with Splenda or similar. There are differing opinions on here about the carb values for rhubarb (ducking hurriedly :wink: ) but it does work. I like sheep's or goat's yoghurt.
Drink plenty of water, and make sure your veg intake is fibrous eg cabbage and leafy greens.
Also oat bran (health food shops etc) which you can sprinkle on/add to almost anything. Shove it in with the stewed rhubarb). I think it's very low carb; someone will tell me if it isn't (Ken?).
If all else fails, I use Andrews LIver Salts (known in my household as 'blasting powder') - a couple of teaspoons in a glass of water at bedtime.
A lesser-known cure, which works for me, is red wine. If necessary, I sit down at about 6pm with a glass of red to watch the news, and am usually on the loo before I finish the glass! Why it works I don't know, but it usually does! Relaxes the system, I suppose.
Also Lindt 90% proof chocolate - which is fairly low carb - has a disastrous effect if you eat too much!
Plenty of options, but I don't recommend trying them all together :shock:
It will remain a problem, I'm afraid. I occasionally eat a small amount of Lizi's Granola (health food shops and some supermarkets) which pushes my carbs up a bit but adds to the fibre.
Best of luck!
Viv 8)