My family member 66 has brain tumor doctor has suggested 2 tumor surgeries one is done and one major surgery is on16 Sept at pgi Chandigarh.. He is thin like skeleton now he is secreating  very white color liquid like phelgum he is not eating anything ..what liquids should i give?? He likes curd , banana ,juice but due to phelgym we can't give.. Or semi solid foods.. He has mouth ulcers also.. Urine is reddish yellow what semi solid foods or liquids goes well for all his health problems i m very confused