How Can Chronic Anemia Be Treated?

I was very anemic last year, hemoglobin had slowly gone lower over a year s time, till 7. Primary told me to take iron pills, three every day, for three months. Hemoglobin came up to 13 about 3-4 months later. I am not taking any now, since last december i think. We ll repeat the blood work later this spring. Problem is my bowels have been ruined by the iron. I can not go anywhere now. When the urge comes, i need to have a bathroom available. I have a bm some days 4 or 5 times. First somewhat formed, subsequent ones looser and diarrhea. I have lots of gas too. We have not discovered the reason for the anemia, since i have a fib, my cardiologist gives the gi doc a hard time, i take pradaxa twice a day. In 2015 i had a colonoscopy, virtual for the first time, no issues if i remember correctly. To be repeated in 2020. I also have a large hiatal hernia, learned you can have blood loss from that too. I have been trying to read about all this, including article : iron supplements with longterm consequences. It does not sound very encouraging, i will discuss w my pcp next week too.