Dejibo,
I want to say that I don't think it is MS, JMO. I can only compare that I have had this and so has a friend of mine without MS. I was going to my GI doctor for my other problem years ago, and while there I had him feel the sort of bulge under my Liver, right above the waistline.

It felt very uncomfortable most of the time when it was there. I was getting it off and on during the last 10 years. I think it started even before that, for I was tested for gallbladder a long time ago.

Many doctors had tested me for gallbladder, liver tests, GI tests upper and lower, many scans and nothing was found. It drove me crazy.

He, being a GI surgeon, said it was a misplaced muscle that can spasm at times. It can bulge and you feel the movement. The bowels tend to set it off at times too. You could have twisted it or pulled it, he said to me.

It goes back into place again. That's what I think it is. I hope you are not having a flare.

When I changed ins and didn't get my "C" years ago, my MS Specialist said don't worry you are covered with the "C" for 5 months, it will still be working for you until you get the med again. So I don't think it is the drug holiday. JMO of course.