calprotectin: how accurate is this test? and post-infectious IBS with UC

Hello, Here is a little background. Sorry for a long post... I was diagnosed with UC in 2011 after a bout of major urgency/frequency/lots of blood. Treatment was Asacol, canasa, rowasa, VSL3 as well as rectal steroids here and there.

Fast forward: back in January after taking several rounds of antibiotics for respiratory infection I noticed things were starting to simmer into a flare. Noticed frequency, urgency, and some (not a lot) of blood. Given a course of rectal steroids (in addition to ramping up the Rowasa, canasa to daily) and then seemed to be almost better.

Then, got food poisoning from a buffet and was sick with vomiting then diarrhea. Initially saw my GI doctor who said this sounded like classic food poisoning it should get better in a week or so. No cultures were taken at that time.

The diarrhea lasted over a month. I should mention that I haven't seen much blood (only a few times saw a teaspoon worth). Finally cultures were taken and something called Calprotectin. The cultures came back negative except for showing some white blood cells. My GI doctor said he thought this could be a "postinfectious IBS" and gave me Xifaxan. Finally the "calprotectin" test came back negative, which he said indicates this is not a UC flare. I have been on the xifaxan for about 5 days and today is the first good day. Every other day I am miserable with about 2 hours worth of diarrhea and cramping, going about 6-15 times per day and just want to curl up on the floor and have my colon removed.

My question: has anyone else experienced this? Is calprotectin only for UC but does it test for Crohns? Is it accurate? Does this mean I do not have UC any longer?

ON a side question: post infectious IBS--will this get better? Is it common for a person to have UC and IBS? It seems strange to me to have both, like really bad luck :-(

Thank you for your post! My last scope was last April which looked ok except for a small Amount of sigmoid inflammation, but overall it was remission. I would like to have a scope soon if this diarrhea doesn't get better.

I think the results are something like above a certain number (50?) indicates inflammation. Above another # indications results in-line with IBD. If yours were normal, it's possible it's something else. It's also possible it was a bad sample. Once i had a normal result when I was flaring. I think retesting could be a good idea, but I'd give the antibiotics some time to work before going crazy.

Thank you so much everyone! I'm going to keep praying that the xifaxan works.