Today I had a rust colored bowel movement

[ckn82]

I'm 35 years old and suffer from IBS. Today when I had my morning bowel movement I noticed the color was reddish-orange, almost rust colored. I have no other symptoms. The only medication I am on is Xanax which I take PRN but I hadn't taken one in 24 hours before the BM.  To be fair, I did try an hard (alcoholic) orange soda the night before, which I had never done before, along with "Spring Oreos" which have pink filling and which I've also never tried.

I freaked out when I saw the color and ran to the drug store to buy an OTC occult fecal blood test. I ran that on my previous two bowel movements and both were negative for blood although the stool retained the rust color.

About 4 years ago I had a colonoscopy and everything looked good. I'm not sure what to do.