Do you menstruate?
Have you been diagnosed with anemia and been told it’s because of your sex and not an underlying medical issue?
If so, print this out and hand it to your doctor as you say these magic words: “86% of women in this study were found to be anemic due to previously undiagnosed internal bleeding. My biological sex is not a disease; and it is likely I have an undiagnosed gastrointestinal illness. Are you willing to work with me to get this solved?”
My celiac disease went undiagnosed for over 30 years because it was easier for doctors to call me weak, fragile, picky, sensitive and female than it was for them to realize I had a genetic disease (and you don’t want to know the various irresponsible, sexist and racist (long story) things medical professionals said to me when I finally got so ill I had to have a diagnosis). This medicalizing of my sex as opposed to actual attention to my health has done permanent, irreversible damage to my body.
Being female is not a disease, and anemia is generally a sign of one. If your doctor says it’s because you menstruate without further and significant investigation: get a new doctor.