Heading to ER soon, what tubes CAN'T we have inserted?

What kind of tubes cant we have inserted in us? I'm probably heading to ER soon bc I can't keep food or liquids in and my surgeoN wants them to hydrate me and give me a swallow test. I know there is something that can't be inserted, can someone remind me? Thanks.

No blind NG tube

The only thing they shouldn't do is a "blind NG (naso gastro) tube". THey need to do this with xray guidance because of our small pouch.

IV's,  barium swallow are OK- but be sure to tell them you have RNY and won't be able to consume the 2 quarts they might give you. Been there- threw most of it up.