Lamb can be a bit of a fatty meat, and asparagus is "high FODMAP". Usually Low Fodmap foods are a bit easier to digest if you have IBS. And spices are not easy for anyone with IBS. I know I can't eat any spices.
I am not sure what you meant by "starch".
I found out that I can eat asparagus, but not too much at a time, and I know this sounds a bit nuts, but I have to peel the stems except for about the last 2 inches from the tender sprouts at the top. It's a fiddly job. I cut the stems into about 2" pieces and peel each one. But then I can eat it! The fibre on the stems was irritating my gut but when I peeled it off -no problem. So it wasn't the Fodmaps that bothered me, it was the fibre.
Also eating a huge meal can be a bit hard on the tummy for some people, but I understand, when you're hungry. I always have a proper dinner in the early evening too. Generally a large-ish meal doesn't upset me but it could with some people.