I was dx with Celiac in 2003 (gluten sensitivity) and despite going on a gluten free diet continued to have bowel problems. Docs kept wanting to pass them off as IBS, but I knew that wasn't it. I was finally dx with Lupus in 2005 and found out what is what was causing my bowel problems as lupus attacks my GI tract. My rheumy put me on Imuran (an immune suppressant drug) and I could tell a difference right away.
I've had 2 colonoscopies over the past 4 years and both were ok, both docs did tell me I had a "loopy / twisted colon". I hope you get some answers soon and begin feeling better!
Trust in the Lord with all thine heart, and lean not unto thine own understanding ~ Proverbs 3:5 ~
DX: Hashimoto's 1999, Celiac Disease (AKA: gluten sensitivity) 2003, Raynaud's 2004, Lupus 2005 and Sjogrens 2006
Meds: Imuran, Plaquenil, Flexeril, Piroxicam, Levoxyl, Folic Acid, Magnesium Citrate and magic mouthwash (as needed for mouthsores)