I Have Noticed A Quivering/fluttering Sensation In My Right Abdomen

I have noticed a quivering/fluttering sensation in my right abdomen for several weeks. It is not painful, but is bothersome. It is generally just below my ribs and sometimes goes down to about the level of my navel. Recently, I began to notice that my upper abdomen felt very hard and uncomfortable. Last evening and today, I have had episodes of watery stools. I am diabetic, have early Hashimoto's and was diagnosed with an autoimmune issue (neurocardiogenic syndrome) last summer.