Just following up here what we've done so far (with limited results, but enough to make life and his daycare lady SANE)...
Elimination Diet for 2 weeks - no change. Obviously because I don't think DS is allergic to anything. Still going 2+ times a day of squishy nastiness everywhere.
Introduced a probiotic - Baby's Jaro Dophilus, refrigerated. Helped reduce the # of poo's to 1-2 a day. But same consistency. So two weeks of ED + probiotic.
Switched to a FODMAP diet (except keeping out berries & melons, still to today) - recommended by a friend. I like this Chart HERE.
Main thing here is to reduce the fructose in his life.
Significant Change, now two weeks in to FODMAP + Probiotic.
Stool is not 100% solid and not consistently only one time a day. But SO MUCH BETTER.
Honestly, I think it was the apples/pears. Eliminating that abundance of fruits had a significant change.
Last weekend hit two weeks of FODMAP + Probiotic, so I felt like I could bring some things back.
I made eggs - he was fine. So, I'm bringing eggs back for sure.
I made him some deli meat (not processed pre-packaged meats, but actually cut from the deli.. which are still weird but at least better) + avocado roll-ups. And he did fine. So I think 1/2 an avocado a day is OK. And I've given small bits of broccoli and they seem to be OK too.
Main thing for him is No Dairy.
We're remaining gluten- and sugar-free at home (I'm loving Stevia), although I'm sure those are not the poo issues.... but they're just good decisions for our house.
And staying away from a ton of fruit. It's made finding snacks more difficult. I cook more. I spend more at Trader Joes. And he eats more carrots & cucumbers instead of fruit.
hope that helps! I've joined a bunch of groups for Fruct-Mal kids (which I don't think DS is), FODMAP/BRAT/GAPS diets, etc. Oh my goodness I've been learning :)
Still not at full solid poo here, but at least it's enough to help trigger him to go on the potty.... so now we're doing some successful potty learning as well. Yippee!!