Ideas on pump and cgm sites

My son is 13 and he wears his cgm on his upper rear and his infusion site on his stomach switching from left to right side.  He has been doing this for a year and I am worried.  He just switched the cgm to his stomach and his infusion to his rear.  The cgm doesnt work so well on his stomach (maybe not enough fat?)  There are only so many spots to rotate these around in the three inch area around his belly and his upper rear.  One if my concerns is there is not enough fat in other areas is this a concern i should have and where do you all wear your sites and cgm's.  Hoping for some ideas and to make him and me more comfortable moving to different spots.

I would appreciate all of your input and opinions very much!

While I don't have a CGM I do have the pump. I used only my bum for it for the first few years, and of course ended up with scar tissue. I now switch from my thighs (which sounds SO much worse than it is, though I use a 13mm instead of 17mm needle) my stomach, my bum, and the “back fat” area just above the pants line. It still doesn’t seem like much, but it helps, I hope. Good luck!

I have a teeny-tiny 8 year old who uses both a pump and a CGM.  We alternate her CGM between her upper bum and the back of her upper arm.  We were getting poor readings from her bum so Dexcom suggested we try her arm.  We get much better readings there.  Her pump sites alternate between her upper bum and her outter thighs.  She is too thin to use her stomach unfortunately.  I am always afraid of her developing scar tissue so I try to rotate as much as we can with what little fat we have to work with.  Good Luck!