Since no one else has responded, I will, while hoping that others may come along with better insights. While in the hospital, did anyone mention the possibility of pacreatitis? It's a common complication with ERCP procedures. Usually, this would be acute pancreatitis, which would require immediate medical attention (which no one avoids because of the terrible pain...which I know from experience). A mild case, though, can linger, cause bloating and discomfort, and often recitifies itself. I assume that if pancreatitis was involved you would have been informed, and if needed, it would have been treated before release. Of course bloating can also be caused by problems with liver function, etc. If your husband is continuing to suffer, I would call your physician. After this many days of discomfort, I think you deserve some answers.
By the way, you might get more responses if you start a thread like this under General Discussion rather than Introductions.
I hope your husband improves soon.