The IBS Diet does not say you need to give up sugar!
I personally have given up sugar and I am SO thankful that I did! I feel SO much better in every area of my life!
That being said...you don't have to do anything.
I have given up any kind of sugar...and also all artificial sweetners. The only sugar I get is from fruit and the almond milk I drink has some organic evaporated cane juice. But it's not much to speak of and I only have about one half cup a day!
If you're interested in giving up sugar, I say go for it! It has certainly improved my quality of life!
And if you want support along the way...I'm here for ya! *hugs* Good luck whatever you decide...and most importantly...feel good