Brief Answer:
Can be Pain killer or worm induced
Detailed Answer:
Dear Friend.
Hi , I am Dr Anshul Varshney , I have read your query in detail , I understand your concern.
Worm infestation itself can lead to
Anemia (low
hemoglobin).
However, i also noticed that she is suffering from Knee
joint pains (that is probably
Osteoarthritis and NOT
Rheumatoid arthritis).
She must be taking pain killers for her knee joint pain, and actually that can cause NSAIDs(Pain killer) induced ulcers and can cause little but continuous bleeding from her stomach/
duodenum, that can cause black tarry stools.
However, since she is anemic, she requires investigations and treatment.
You should not consult a local doctor for this problem, you need to see a good physician in your area.
In the area you have mentioned, you should go to Banaras Hindu University (BHU).
I suggest following investigations:
1. Hemogram with RBC Indices.
2. Iron Profile.
3. Blood Picture
4. Stool examination
5. UGI
Endoscopy.
6. Stool For occult blood.
This is ideal workup. In case you can not afford, share her all available investigations with me, so that i can tell you all possible ways to treat this.
This is my personal opinion based on details available here. If you still have any query you may please ask me.
Stay Healthy.
Dr Anshul Varshney , MD