I have had a lot of trouble with Lactated Ringers in the past 6-8 months. Each time the symptoms got worse and came on stronger. I would get sydden sharp pounding headaches and my stomach would start to burn, but I never understood why. I was under the impression the IV just had saline and some minerals. But this last time I realized I had no idea what "sodium lactate" was. Upon further research I found out it is lactic acid taken from the fermentation of corn sugar. If you have an actual corn allergy then it is VITAL that you do not get anywhere near a Lactated Ringer. I myself have an intolerance to corn and it's something that hit me like a ton a brinks.
The more I researched the more I realized that a lot of these medical products contain corn. For example, dissolve-able stitches have corn starch on them as a coating, and many other ready made IV's contain dextrose which, you guessed it, is corn glucose. My searching led to this amazing Google Doc that is linked HERE, which is a comprehensive list of things you can and cannot have in a hospital setting if you have a corn allergy or intolerance. It's essentially a handy printable to keep if you ever find yourself in an Emergency Room or Hospital of any kind.
So, what can you do if you need IV hydration or nutrients? There are a few options. You can simply get Saline which is safe, or you can ask for (non-lactated) Ringer's solution. But you do need to make sure it does not have dextrose in it, because some might.
I hope this can be helpful to someone out there who is confused why a hydration IV made them feel so much worse. The IV's used to help me a lot, but recently when I felt worse for wear I knew something was happening, and now I know! As I always say, being a patient is a full time job which fully requires one to be their own advocate.