How long did you make the tube? I've never heard of such a thing happening. Either the tube was cut too short, should have been nine or ten inches, or it was thin and too flexible.
Crop surgery should be done. It's relatively simple and low risk. Here are my instructions.
Supplies to assemble:
A helper
Vetericyn wound spray
Betadine or alcohol
Saline wound flush
Sharp, sterilized cutting tool such as a one-sided razor blade or Xacto knife.
Sterile gauze
Tube of super glue
Latex gloves
Bath towel
Scissors to cut away feathers from incision site
Surgery:
-Wrap hen securely in a bath towel confining wings and feet, but leaving the crop exposed. No anesthesia is required. No pain meds.
-Have your helper hold the hen on her back on a hard surface or table.
-Locate the spot where the lump is most concentrated.
-Trim her feathers away so just skin is exposed.
-Prep the site with Betadine or alcohol to remove external bacteria.
Make a one inch incision in the skin. Do not cut any deeper than the outer layer. This will expose the crop sack.
Next, cut a one-inch opening into the crop sack, slightly offset to the outer cut. This is very important. You should be able to see the obstruction, grass or maybe something else that shouldn't be in there.
Putting slight pressure on the crop, push the obstruction toward the opening and pull it out. Continue until you can't get anything else out of it.
Irrigate the inside of the crop with a generous amount of saline until the saline comes out clean.
Dry the incisions by patting with sterile gauze. First apply super glue to the edges of the inner incision. Hold the tissue together until it bonds, about one minute. If it doesn't hold, apply more glue and continue to hold it until it bonds.
Glue the outer incision as you just did the inner one. Spray the incision liberally with Vetericyn. This promotes the tissue to grow together and heal. Do this twice a day for the next two days.
Feed only soft food such as yogurt, soft boiled egg, apple sauce, or gruel made from mixing water into her feed until it's soupy for the week following surgery. Give her a dose of Nutri-drench each day for five days.