First are you IBS-C or D? I'm D and I take
2 Imodium,
1 Bentyl ( a prescription anti spasmodic available here in the US, generic name dicyclomine)
2 Phazyme.
(...and a partridge in a pear tree!!)
Then I drink a glass of Metamucil.
Then I eat only Heather's super safe soluble fiber food list for two days.