Hello Natalie86 and thanks for posting, 

I am sorry to learn about the unpleasant symptoms you are having and can understand you wanting to find out what is causing them.  A lot of people run their symptoms and tests results by us and ask about other people's experiences, but it doesn't necessary shed much light on things as each situation can vary depending on the context. Unfortunately we are unable to help diagnose anyone.  

I think FIT tests (which look for hidden bleeding in poo)  arranged by the GP are more often used to assess someone with bowel symptoms than someone with acid reflux and particularly to look into the possibility of bowel cancer.  My understanding is that a FIT test result under 10 ug/ml is generally reported as a negative result overall. But all test results have to be interpreted in context depending on what symptoms someone is having, whether these can be explained and also their age - the likelihood of cancer is much less in younger people in whom it isn't so common. So what happens next probably would depend on the situation and what the GP thinks might be going on. 

In women having periods, blood iron levels can be low because iron gets used up in the production of new red blood cells to replace menstrual blood loss - (ferritin stores iron in the blood). Diet can also account for having less iron in the system. 

Because no test can ever be perfect 100% all of the time, with any negative FIT result, it is important for the GP to assess the result in context and for patients to keep an eye on any ongoing symptoms and let the GP know if things get worse so they can re-assess the situation. 

All I can suggest is talking things over with the GP again, asking about the FIT result and if the low iron levels should be monitored or could be a cause for concern. They are in the best position to explain.  

I hope that the endoscopy appointment comes through soon and that things improve for you. 

If you want to talk anything over, please do give us a call on  Freephone 0808 800 4040, we are around weekdays 9-5. 

Best wishes, 

Julia