I do not have IBS-D, (and my IBS-C is history) but I do have issues with dry skin, and my wife has even more dry skin issues. Winter (in Minnesota) increases the challenge, and I assume that diarhea, with it's dehydrating tendency would certainly add to it. Also, if you limit your dietary oils and fats (which many IBS'rs do), that doesn't help the situation either.
A couple years ago, in an attempt to eat healthier, I had cut fats and oils almost to nothing in my diet. My skin started looking like one of those dried up lake beds.
I have since brought oils back into my diet. I still limit my fat intake. My skin has thanked me for that. I have also tried several oils and lotions for my skin, and am convinced each person needs to go through trial and error to see what works for them.
I use a olive oil/aloe blend soap called "Kiss My Face" for showers and washing. Many soaps will dry your skin, especially avoid anything astingent, (unlike the old Zest commercial a little soap film can benefit you if it is not disagreeable to your body, or full of chemicals). Also, avoid "hot" showers. Go for as warm as is comfortable, even cool if you can handle it.
I have had little luck with lotion, I think partly because they tend to have more water than oil in them, and oil is what works best for me. For maintenance of my skin I will use a cold pressed sesame oil (very warming) or olive oil, with nothing added (no perfumes, etc).
My wife has suffered from chronic dry lips for about 40 years. She has used a wide range of products, even prescriptions, and has finally discovered the blessing of vitamin E oil. She says they have never been so soft (and I can vouch for at least the last 26 years).
Her feet have been drying up for several years and are very crusty and cracking. For the past month she has been soaking them at night, in straight Castor oil (recommended by her natural care doctor). After soaking she puts socks on and plastic bags for overnight. Although she has not been as diligent as recommended, there has still been a dramatic improvement (my guess is that this could helpful for your hands, since they suffer so much during the day).
She has also been very happy with a vitamin E/castor oil blend for her body as well. But continues to use a variety of lotions, mostly for convenience.
One thing I have learned is whether you use lotions or oils, natural or other, they need to be washed off daily, because they seem to cause irritation if left on too long. And don't use old lotions or oils. They do spoil over time.
Experiment with all types. Coconut oils is a little on the cool side, but may prove too light. olive and sunflower are medium, sesame warmer and castor the warmest. and anything with aloe or vitamin E in it will assist with any needed healing.
Hope you find something here that is helpful.
I also wanted to say that I always enjoy reading your comments to others on this forum. You are always so pleasant and supportive. I wish you well.