Advice on next steps

Is there anything we can do to speed up the process to get to a diagnosis?

My wife has had chronic diarrhea, malabsorption, and weight loss for over 4 months.  She continues to lose weight, from 140 to new low 113.2 today.  The GI at Wake has her on a 2 week gluten-free diet.  We are 3-days into the diet with no change.  We know that a test showed low pancreatic enzymes and a biopsy severe colitis in her lower colon (GI said it looks like colitis caused by acute infection, but no infection found).  Many tests (stool/blood) and biopsies have been done, all negative.

Symptoms: Eczema(spots don't go away), hair loss(minor), hidradenitis suppurativa, numerous infections, enlarged spleen (removed), chronic diarrhea/constipation (10+ years), and now severe diarrhea w/ malabsorption

Current treatment:  1-2L IV, Lialda (4/day), prednisone 40 mg/day, enzymes MT-10 (2/meal), pot KLOR-20 (4/day), gluten-free diet for 2 weeks. GI surprised enzymes not helping, but does not put as much stock in the enzyme test as his collegues.

History:
1997: diagnosed Ulcerative Colitis (mild)
2004: C-section, several months after cellulitis with abscess
2005: severe pneumonia, w/ sepsis (Xigris), pulmonary abscess from pneumonia (Primaxin), enlarged spleen
2006: enlarged spleen removed laparoscopically
2008: C-Section, cellulits
2009:
Feb:  chronic diarrhea started, watery, a bit oily, chunks of food, frothy at times
Mar:  Colonoscopy - microscopic colitis, hospital c-diff (only one test had weak positive) (flagyl, 2 courses vancomycin), no change, then prednisone 10mg/day 5 days, 5 mg 7 days, diarrhea slowed a little while on steroid
May: hospital dehydration, low potassium (2.3), referred to Wake Forest GI
Jun: Hospital pneumonia, UTI, low pot(3.2) (vancomycin/doxycycline) (IV home, potassium)
- MRI at Wake (suspected IBD) neg. (Lialda 1.2 mg (2/day), continue other meds)
- Wake Colonoscopy/EGD – biopsy severe colitis colon, not ulcerative, not c-diff, no celiac.