Hello and welcome to the forum. That's such a lot that you've been through with this health issue. Please work with a gastroenterologist to determine cause and treatment plans. Yes, this could be a manifestation of IBS. IBS can look different and take different paths with different people making it a little bit of a difficult condition to diagnose. But essential to do so. They have many medications to help. Are you losing weight with the current situation? I do want to point out that one can become so constipated that they have impaction in the bowel which could lead to vomiting. You do need to be evaluated for this right away if you haven't already. Please give us an update.