DX with IBS-C--Not sure about the symptoms?

[chopperchickie]

I have been in the hospital 5 times over the past 4 months.  I get sudden, severe abdominal distention/bloating, soft tissue pitted edema in my right leg, and usually have a sudden weight gain.  The first time I went I had a CT scan and it was noted that I had a heavy colonic load and peripheral abdominal edema.  I've had every GI test in the world and the GI specialist told me that every test came out normal and that she was able to rule out everything so she was going to DX me with IBS-C and there was nothing more they could do.  I don't think I have any of the symptoms of IBS and I am in need of help.  The ER Dr told me it was time to see a specialist but didn't tell me what kind upon asking.  My symptoms include: soft pitted edema, central obesity (please note I gained 30 pounds in 7 days which caused my first hospital trip), since then I have gained 50 pounds in 4 months, abdominal bloating and distention, abdominal tenderness usually a hot, burning feeling up and down the center of my abs. I am pretty regular with or without taking amitiza (dr told me to take) I don't get pains when I need to use the restroom, I don't alternate between constipation and diarrhea,  It should be noted that I am a 36 yo female that is very healh conscious.  I've had blood work done and I don't have celiac, hypothyroid, or PCOS.  Does any other female experience these symptoms?