Hey Saltire - sorry you've had such a "dire" time of things, glad the clarithromycin seems to be working. I'm currently on the same antibiotic (...6 week cough/chest infection...) which fingers crossed also seems to be helping!
Picked up some probiotics at Holland and Barrett too, thought I'd share some of the discussion I had there (this was after my local pharmacy didn't stock any!!! - in South Africa I recall you'd get AB and probiotics at the same time) Basically, I was told to take the probiotics a few hours after the AB, otherwise it would just negate the effect completely which makes sense to me. The box that I got also talks about taking probiotics after the course of AB has finished, starting 2 days later. So what I'm currently doing is taking AB morning/evening, and just before bedtime one tablet of probiotics. I'll continue that until after the AB are finished, then switch to probiotics twice a day. So far, seems to be working for me (or at least keeps the digestion ticking over!)
All the best - hope you're much better very soon!!
-Anke