Azathioprine stopped working?? What next??

Hi all

I never usually post on here because I have been lucky enough to be symptom free for nearly 6 years on azathioprine (since diagnosis). Apart from the routine blood tests and my annual check ups I forget that I have got anything wrong with me, and have even had a perfect pregnancy & darling baby whilst taking aza.

For the past year my blood has showed only a very low level of aza (tgn test I think it's called) but nobody was concerned as I was so well and at my last check up in June we discussed me coming off all meds to see if I stayed in remission. That has jinxed everything!!

I stayed on the Aza but started getting mild symptoms in July, cramping 2-3 formed stools a day but with mucus and some flecks of red blood in the mucus (I have crohns colitis). A 2 week course of metronidazole was prescribed and I was good as new a few days into taking it.

6 weeks later, the same symptoms started creeping in again!! I am having a colonoscopy this Friday and am a week in to another course of metronidazole (seems to be working, feeling better and normal BMs) but consultant wants to see what's going on

My question is...has the Aza stopped working?? And why is it that I was in the therapeutic range for years and now I seem to only be absorbing a small amount? I am definitely heavier than what I was when I was diagnosed, but only by about 7-8lbs so not enough to make a huge difference.

I have anxiety issues and the thought of being sick and changing mess makes me really worried 😩

Hi you didn't mention on how much azathioprine you are on.

I'm currently on 100 mg. I had to reduce from 150 mg. Back in 2007 I was on azathioprine as well and I started flaring. My GI took me off of aza completely which was a mistake I now know. I should have only taken pred. I started on aza again in 2013 and I've been in remission again.

Have you done a Prometheus test to check if you're in the therapeutic range? What about 6mp as alternative?