Brief Answer:
detailed answer below

Detailed Answer:
Hello and welcome XXXXXXX

I completely understand your issue and also that you are in pain and heavy bleeding.

Unfortunately this is not uncommon with long term use of these pills.

The pills contain estrogen and progesterone homones. Normally both these hormones are present and secreted in our body naturally in a particular rhythm and they regulate the menstrual cycle. In conditions like endometriosis there is abnormal growth of the uterine lining at unwanted places. So we do not want the lining to grow and hence stop our own body hormones from getting secreted. So if hormones are given artificially [ as tablets natazia] then we hope that these implants will not grow and cause trouble and after continuous use the disease is suppressed and cured in some women.

However the issue is that the body and the uterus is not used to this type of hormonal stimulus. So the uterine lining does grow for some day under the influence of artificial hormones and stays grown and then bleeding occurs despite the tablet as the uterus has either got used to it or the tablet can no longer control the lining. Also in some cases the lining becomes very thin and friable and bleeds. Such bleeding is called breakthrough bleeding and it can be very heavy and can occur for prolonged period. So you will need to see your doctor for this. Drugs like tranexamic acid and ethamsylate help control it.

Also it is advisable to stop the tablet and let the uterine lining regenerate to prevent such bleeding in future.

Other management methods for endometriosis like hormonal intrauterine devices and implants can be tried. Other options are surgery to remove the implants if they continue to persist.

So this bleeding is not unusual but will need therapy. So please see your doctor.

Do not worry and take care.
Hope this satisfies your query.
Thanks for using HCM.     
Feel free to ask any more questions that you may have.
Dr Madhuri Bagde
Consultant Obstetrician and Gynecologist

---