Hey there, sorry to hear your stomach isn’t getting along with Huel. Huel is a high fibre food, so is often not seen as suitable for people suffering with IBS. However, a number of people who do have IBS are using Huel. Check out this thread or any others by using the search bar above and it might help with some advice.
How much are you eating day to day? Are you still having 3 square meals a day, with one of those as Huel, then the rest full meals. Or is the protein and veg you’re having just snacks? It might be that you have unwittingly lowered your calorie intake far below what you’re used to. Check out this here to see how many calories you need per day.