I found out I had gallstones during my hcv workup, never knew I had them. I took interferon for 12 weeks in 2014, and have had no problems then or now.
I am not sure I fit your survey. I had INF tx in the mid 90s - and had digestive problems after, but had them befor, too, so cannot separate them out - fast forward to 2014 - dx'd with gallstones and had to have them removed.
Is such kind of pain a listed side effect of interferon? I have to say I'm surprised that a doctor would opt for interferon treatment (50% cure rate) in 2015 when the obvious choice are the new line of antiviral drugs, based of sofosbuvir (95% cure rate).