What's the difference between Fybogel Mebeverine and Fybogel for constipation?

[hellohelp]

Sorry, having trouble understanding the packaging as I'm not sure what the differences are between conditions

One fybogel is for IBS and helps maintain bowel regularity
The other fybogel is Hi Fibre and for constipation

I have constipation and am supposed to take the Hi Fibre one but after the gp gave me a different brand I didn't like the taste of I bought my own (wrong) Fybogel which is for IBS. What will that do?
I drank the sachet before realising

Mebeverine can help with cramps associated with IBS. One dose is unlikely to do much to you, though it can cause constipation on its own if taken regularly, though the Fybogel will offset that.

Thanks @helly29!
Kicking myself as 2 sips in I could taste it wasn't what it should have been but I just kept stirring and drank it anyway. The wrong brand but right stuff is much better I should have stuck with that
Back to the chemist tomorrow lol. Thank you!