The best replacement for barium is gastrografin.

The best alternatives to barium are rated as following:
★★★★★  gastrografin
★★★  endoscopy
★★★  gastrografin swallow
★★  colonoscopy
★  gastrografin enema
★  omnipaque
★  water soluble contrast
★  barite
  gastrograffin
  magnesium more reactive
  barium sulfate
  strontium
  antimony
  gastrographin

Your alternative for barium is not listed? Suggest!
Speaking about barium, one probably shouldn't forget about ct scan.

Other search terms related to barium and their ratings are:
★★★★★ ct scan
★ cat scan
★ small bowel follow through
You have in mind a companion for barium and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of barium in all years. Click on graph for more.
barium
gastrografin
endoscopy