Scott, yes the pump is uncomfortable and your descript
ion of sucking your guts in is accurate. I had the biggest trouble with it pulling my scrotum inside. I found a set of 3 inerts/reducers that really help with the sucking feeling and gives a much more powerful seal at the same time. I use silicone rings and have no big problem with putting one on, just roll off the end of the pump and it's there. I have had some painful removals when I took one off without plenty of lube to help it slide off. Can't say that the routi9ne use of the pump or rings are painful, at best I can describe them as uncomfortable. But a necessary evil for those of us who wish to keep treasured tissues infused with blood and stretched so there isn't any more shrinkage.