What position do you sleep in?  Sleeping on your belly allows gravity to assist.  Sleeping on your side is better than sleeping on your back.  Only problem with belly sleeping is it can lead to neck or lower back pain, but swinging a knee out to a side can help alleviate the pressure.

As for diet start with the basics.  Have lunch around midday, for evening meal go back to the post op diet, also eat as far from bedtime as possible.

Do you take fibre?  If so are you sure it helps?  I started taking fibre and thought it helped, but I was actually noticeably better when I stopped taking it (looser consistency but less cramping). 

Try to avoid sweet desserts after tea too (and food with yeast etc) . The sugar can cause fermentation which leads to gas.

Probiotic is a good idea too, plenty of other posts on that.  

I can empathise completely! I take loperamide and also avoid fatty/rich foods avoid high fibre and I am currently on antibiotics for pouchitis that helps! Avoid eating too late. I don’t use a diaper but line my underwear with loo roll every night ! Sadly I’ve got used to it apart from the occasional night when I get deeply upset about it! I hope this helps part way.

I have relatively small amounts of fecal incontinence almost every night. I use womens' sanitary towels, the max absorbancy ones with wings (essential feature!). I find them discrete but adequate with snug underwear.

There are lots of incontinence supplies but mostly for urinary and I didn't find anything that worked better for me.

I know the female products are pretty effective, just put them more on the back side.  I now use men's depends, shift them to the underside and back and they work pretty well.  The fact it's for men makes it better!

If you are having trouble emptying, strongly consider a bidet with a turbo or "enema" function. That makes my quality of life 5x better. I miss my bidet more than my family when I travel! The bidet significantly reduces my # of Bms and allows me to "start on empty" at times when I am at higher risk for incontinence.

i also use Always Infinity shifted toward the back, when extra protection is needed, and I tuck a portion of a cotton ball right up inside my anus-that has also been a life changer for me. 

Without my bidet and cotton ball (and I also take meds to treat chronic pouchitis), I think I would be on disability. with them, although unorthodox, I am nearly functionally normal (still have small accidents occasionally-1x/week?) but have learned to live with it. Without the bidet and cotton ball my incontince would be daily.

I just sleep in a diaper.  It’s almost NEVER necessary, but that way I don’t worry.  My husband, the most wonderful man in the world, still thinks I’m sexy.  The rare “accident” doesn’t seem to have anything to do with what I’ve eaten that day—they’re just random.