Help!! Does this sound like a flare up?

I'm really struggling here and could use some help.  I've had IBS for about 5 years now (I'm 28) but it's been predominately with constipation and mucus in my stools.  I gave birth 6 weeks ago and since then I've had a bit more diarrhea but just a small amount, every time I go to the bathroom, and there is no cramping or pain involved with it.  Last night I had a ton of diarrhea about 3 hours after finishing dinner (take out Chinese) and continued to until my bowels were empty.  I also woke up with it 2x's during the night.  Today I've been very hungry but eating bland foods like bananas, toast, broth, crackers, and mashed potatoes as well as sipping water.  After every time I eat, within 2 hours I'll get some cramping and diarrhea again.  I even just took a small sip of water and had more diarrhea within 10 minutes of that.  I had a stomach virus 3 weeks ago with severe diarrhea, cramping, and dry heaves that ended me in the ER with dehydration.  My stomach hasn't been quite the same since then but it also hasn't been this bad until last night.  I did have a rough day emotionally yesterday with some issues with post-partum depression and then had the Chinese food for dinner so I'm wondering if one or both of those things triggered a flare up.  I've never had diarrhea predominent IBS, does this sound like a flare up?  If so, does anyone have any suggestions on how to treat it or what I might try eating since everything is going right through me?  How long do these flare ups usually last?  I'm concerned about getting dehydrated again since even water triggers the diarrhea and I'm also nursing my 6 week old.  I would GREATLY appreciate any help or input!  Thanks so much.

Actually, it sounds as if to me you've nabbed yourself another viral or bacterial infection.  Could be from that Chinese food...you never know with take-out!  I am willing to bet it will subside within the next 12-24 hours.  In the meantime, drink diluted Gatorade (diluting it helps to cut down the sugar, which can make diarrhea worse, while still giving you much-needed electrolytes) and don't eat until it passes!  If it's not an infection, it could be that your IBS is simply changing course, like dbab suggested.

Thanks so much for the input everyone!  The diarrhea has subsided a bit since early this morning.  I've had one bout of it after sipping water for a few hours and having half a piece of plain toast.  I did call my dr's office and because I've had diarrhea 6x's today and am having symptoms of dehydration, they want me to come in so I have an appointment in a couple of hours.  I also checked on the safety of Immodium while breastfeeding and if I need to take it, it should be okay.  But if this is a viral or bacterial thing I don't want to take any so we'll see what the doc says.  I do take acidophilus capsules and used to take fiber supplements but haven't for a couple of months.  Thanks again for the help!