I think you are on the right track with probiotics although it could take you some time to see results. VSL#3 and other probiotics (L. reuterii, Lactobacillus) got me to a healthy place and now I don't take them, only when needed.
Keep a journal of what you do and then look back in 6 months and see if you have gotten improvement.
Here is a link with a quote below from study report by National Institute of Health:
www.ncbi.nlm.nih.gov/pmc/articles/PMC3002586/Basically saying that certain probiotics are
as effective as mesalamine in relapse rates.
With regard to maintenance of UC remission, probiotics have been tested in a larger number of patients (Table 3). One trial by Kruis and colleagues tested E. coli Nissle 1917 and found no difference in relapse rates in patients on a probiotic versus mesalamine [Kruis et al. 2004]. A trial by Zocco and colleagues also found no difference in relapse rates at 6 or 12 months when comparing Lactobacillus GG with mesalamine with a combination of the two [Zocco et al. 2006]. Those patients who took the probiotic did appear to have a longer time to relapse. All of these studies support the idea that probiotics may be as effective as mesalamine in maintaining remission in the short-term trials.Do some searches on Google using"nih" and "probiotics ulcerative colitis" and see which ones you want to try--one by one--not all at one time.
I've used this one
www.amazon.com/New-NatureS-Primadophilus-Reuteri-Pearls/dp/B00185OHAA successfully. Also taken Lactobacillus, not sure which strain.
Both were helpful and when I have an antibiotic RX I take larger amount a couple hours apart from antibiotic.
If you have no problem with dairy buy the kind that has "live cultures" of Lactobacillus but try and keep sugar intake low. Sugar is inflammatory and fake sugar is also bad for some (including me). Read the label ingredients and avoid carageenan.
Good luck.
One last idea:find some empty time release capsules and put some VSL#3 in them to take orally. Might help to get the probiotics to a lower area and be a back-up to your probiotic enema.