Pinky
I had Botox without local anaesthetic (because it is best given without it according to my CSR - read my "No LIS, more Botox thread", No GA, and I was awake....) and he used an ultrasound the whole time. It is the size of a man's finger, and they lube it before they use it. I have dreaded this BIG (my imagination) monster thing, and when I saw I almost laughed.... I was given something to relax in my vein.
I really do know what you say about painful exams. I always tell the CRS to put as little pressure as possible on the fissure. Mine is at 6 o'clock and I tell him to "press" at 12 o'clock when going in. I have finally found a wonderful CRS, am happy because of that. He will not do LIS at this point because my external sphincter is weak now (because of Botox maybe, but de can't be sure), so he does exactly what you say :)
Don't dread the ultrasound, at least not the size of it. Ask if you can get something that relaxes you...
Hang in there dear, don't give up - post as much as you need and you'll get support. I have learned that this is a wonderful place to be whether you are in pain, or you aren't. You can get support and give support
Corsica