Hi and welcome to HW! :
Yes, yes, yes, it certainly can.
I have IBS and I can go from D to constipation to vomiting all in one day and even my doctor knows it's anxiety. I keep a food journal so I can figure out what foods are the very worst for me. I also take bulking agents like metamucil to, well, "bulk me out!"
The insomnia is probably related as well to the anxiety. have you considered getting some help for your anxiety? It may reduce your problems (physical and mental) if you can talk all of this out. Plus you can chat to us anytime you want! Again, welcome
Panic Attack Survivor
Weekend Warrior Princess