Hirschsprung’s disease is interesting, and sounds like it fits some symptoms (mine as well, haha). But given the fact of your eating disorder history and all of the other restrictive dieting you’ve done, it’s much much more likely that everything you’re experiencing is the result of a damaged metabolism from years of malnutrition.
For instance, the electrolyte imbalance is very likely just a symptom of your body’s digestive function being compromised (which is quite obvious to you), and that can improve if you work on refeeding. Before adding any sort of electrolye supplement, I think you should try to Eat for Heat without all of the supplements (ie no castor oil, no juices first thing in the morning, etc). Moreover, if you continue guessing at which electrolytes are missing, you can create more imbalances and more problems. So if you feel that your electrolyte imbalance symptoms don’t get better with just eating more of the things I’ve suggested, and you want to supplement, you should consider first getting a blood/urine test from the doctor to analyze your vit/min levels to figure out what you might really be missing.
But ultimately, like I said, I think a lot of those issues can go away if you focus on refeeding. That’s what happened in my case!