Because of Tb,you had fluid in abdomen and also in lungs.Hope you have completed the Course of Anti TB drugs.
Due to Tuberculosis
,there is possibility of Stricture formation in small intestine
which causes narrowing and pain.This can be excluded only by Barium meal
follow through test done by Radiologist
Another possibility is the Adhesions between loops of Small intestine.
You can go for A Diagnostic Laparoscopy
to rule out abdominal pathology.
Regarding lungs,go for a X ray chest PA view/CT scan Chest for any pathology.
Once your TB is completely cured,you can put on weight.
Please consult TBCD(Tuberculosis and Chest disease) specialist and Surgical Gastroenterologist and proceed .
Wish you good health