Indeed. I have certainly been misdiagnosed with something for 20 years now. Over time I have found many little things that help, and they have added up enough so that I can function like a normal human being now.
It's nearly impossible to get past the "it's psychosomatic" barrier most doctors have. They managed to convince me of it once, and I accepted psychiatric management for several years, which led to an exponential worsening of my obviously (or so you'd think) very physical condition until I decided to end that approach after an entire team of specialists were stumped; towards the end, one dared suggest: "I think there's actually something wrong with his stomach..." and around that time I decided to get out of there.
Many doctors completely shut down after a certain, usually very low, threshold of tests. Most shut down after ordering 2 sets of tests and not finding anything definitive; beyond that point they become 100% confident it's in my mind, and replace their respectful tone with a condescending one, with accusatory implications like "you went and made us do a CT scan and there was nothing!"
I wish, like in the case described in this article, my parents acted as my champions when it hit at age 11. Instead they deemed that my needs were excessive for my lowly social status and thus should stop bringing it up to them. Characterizing my demands as a form of misconduct served as a pretext to shut me down, with force if I were to insist.