EBF poop suddenly turned dark reddish brown--should I be concerned?

[Blanca78]

DD is 4.5 months old. Over the last week her poop has gone from the typical yellow seedy (albeit brownish yellow) to very liquid, orangey/reddish brown--it reminds me of maple syrup--with few seeds. I haven't notably changed my diet or our nursing habits, so I'm not sure what's going on. This has also accompanied sleeping disturbances, which I had chalked up to the 4 month sleep regression. At her WBV yesterday the doctor didn't seem concerned, only mentioned that there is a stomach bug going around and it could be that, but the only thing to do was to ride it out.

 I told her I didn't THINK there was blood in the stool but it was awfully reddish today (kinda...burnt umber?) and now I'm wondering if I should be concerned. DD doesn't seem uncomfortable, though, and last night actually slept really well.

Anyone seen this color? I don't know why it's so much less seedy and such a drastically different color. Should I be worried?

[Adaline'sMama]

I think its probably fine. Has it passed? Has she pooped again yet?

[Blanca78]

Nope, still the same color. It's also much smellier than usual and no "seeds" that I see. She seems gassier, too. I'm wondering if the doctor was right and it is some kind of mild bug--she doesn't seem otherwise sick, just kinda fussy (but no fever). I thought maybe she's not getting enough hindmilk, but nothing's really changed about her nursing, so I don't know.