Well, Connor and I just arrived home after being at the doctor's office for nearly four hours. What we're thinking is going on, is that his entire colon is full of old, hard stool. What is able to make it around this stool is what we're experiencing, tiny, semi-liquid stools, and very frequent. The 'sandy/grit' we're thinking might be just tiny pieces of the old stool that's 'stuck' coming off as this more liquid stool passes. (obviously stop reading if you have no desire to read about poop, colons, enemas, etc.)
He had an x-ray done, and after two pediatricians, two radiologists and our nurse practitioner reviewed and then also consulted with a GI doctor, that's what they're thinking is up. We've been experiencing this with him for at least 6+ weeks, and they think that's entirely possible that it could have been 'stuck' for that long and probably just continuing to get worse (we went through 5 pull ups from 9:45-1230 at the doctor's office). They're also still running tests just in case for parasites, bacteria (more than normal anyways) and to see if there is blood in the stool. At this time, there is no reason to believe that it is connected to his Hirschsprung's Disease at birth. They however do typically see this in older kids that 'hold it in' and avoid going. Not sure if Connor 'knew' that he's been holding it in or not.
For reference, here's a diagram indicating where the colon is. They think it's pretty full from the start of it (marked large intestine) to near the end into the Sigmoid colon.
So...we're to give him an enema every night for the next three nights and go back on Friday for another x-ray to see if we've successfully cleared him out. If so, we'll probably begin conversations about how to prevent this again, or try to figure out what caused it in the first place. The nurse practitioner (Vicky Parsons, for any locals that are curious) was wonderful (yeah for nurse practitioners!) and has a daughter that's been through something similar, so it's always comforting to know they've potentially had first hand experience. She even gave me her cell phone number in case I have questions later today/tonight when administering the enema (there may have been a look of extreme panic on my face when we started talking about enemas...) I'm just so glad we took him in today and started the process of fixing it. We are feeling pretty terrible about all the 'punishing' we've done, taking toys away, etc., but how were we to know.
I asked for a picture of his x-ray, which she wasn't able to give me but said I could request it from the diagnostics department, so I will try that on Friday when we go back.