Pain in stomach from last 3 to 4 months.

My sister had stomach pain from last 3 to 4 months. She gone for doctor advice. And the doctor checked some test and said that she had increased size of liver. Because of that she had intolerable pain in stomach. She went 2 to 3 doctors and take medicine but she has not proper improvement in her health. She couldn't be digested even little quantity of oily food, apple and heavy meal from last 3 to 4 months. She is taking only Daliya and Khichdi type meal. She is suffering from weight-loss problem and in that period she had loose motion, fever, cough and cold. At present she had cough and weight-loss problem. But she is taking very light meal. If she would take very little heavy meal she would face digestive problems and pain in stomach. So please advice me what should we do for proper improvement.