Over here in France, they automatically give a script for Brewer's yeast along with each script for antibiotics...I didn't get it back in the 80's but now the science backs up the idea of putting the good flora back once the bad have been irradicated...
You can take probiotics as well if you feel runny or bubbly or gassy once you finish...a 5-7 day run should not destroy your pouch but eating some yogurt daily wouldn't hurt either.
Sharon