Hi Uniform Charlie,
There have been quite a few publications on the potential role of adherent-invasive E. coli in IBD, particularly Crohn's Disease I believe. It is uncertain whether it is merely a bystander organism, complicating factor, or may even be a cause, it's really unclear. However, these drugs always fill me hope as, at the very least, it may remove one suspect from the line-up, or may uncover another piece of the puzzle. At the very least it is a pathogen, so at least these targeted agents shouldn't have a detrimental effect.
Links to some papers regarding AIEC in IBD
https://www.jci.org/articles/view/46333
http://www.ncbi.nlm.nih.gov/pubmed/17476674