There are different dosages depending on your symptoms and your wallet size
. If your insurance covers it the least expensive way to take it is by Rx from your doctor as VSL DS. The DS stands for Double Strength. This is the "therapeutic" dose and I'm sorry that I don't know how often you take it a day (I never took that dose). You can do a search on the VSL site or Google to find out.
I order VSL#3 (not DS) directly from the company online and it is delivered directly to me in ice packs in 2 days. I take 1 (unflavored) sachet in water every night. The sachet packets have a lot more probiotics in them than the pills do. I also make SCD yogurt with VSL#3 just because it's what I have in the house to use. Would be cheaper to use another probiotic for yogurt-making.
I didn't work up to taking it and don't remember any bad symptoms when I started it years ago but whenever I try something new I like to do it on a day nothing important is planned, just in case. Some people report gassiness in the beginning.
Should you wait? No, I wouldn't.
BTW are you using rectal meds like mesalamine enema or Canasa? Add those to your "to do" list if not, good results expected.