your thoughts on these 2 "signs"

Ds has always had abdominal distention, and tons of gas. Now, at 21 months, his belly waxes and wanes but is generally very distended. I know that some distention is a normal physiological occurrance for toddlers on account of their spinal curvature, but wonering if anyone here as any insight or experience with this.

I know it's gas, in part, and probably a sign of some intolerance to something he's eating gernerally. We've been on an ED (gluten, soy, corn, dairy, egg) for over 2 months, though not very strict about soy derivatives because I didn't think soy was a culprit.

The second sign is genital grabbing at bedtime. He started this a few weeks ago, after we nurse and lie down, if he's had an eczema/red face flare-up recently he will often reach down and try to grab at, or just signal to one or all of his parts. He's usually wearing unders so I haven't been able to tell exactly what he's bothered by. And this motion is usually accompanied by fussing and being upset, kind of whiney, to full on crying. There is no redness or inflammation and he has never had any diaper rash. My first thougt was yeast, but we don't seem to have any other yeast s/sx. He eats virtually no sugars, save for bananas and occaisonal maple syrup. But still, yeast was my first thought. Anyone have any insight on this one?

Many thanks!!!!!