shifa

Hello everyone , My father is 59 years old and he had his gastric bypass surgery 6 months back , earlier he was 125 kgs now he is 93 kgs. His weight reduction process is slow than expected. He is religiously following the diet chart and suppliments prescribed to him though he is too lazy to exercise. But our major concern is , he is feeling sick and tired all the time . Last to last month he was daignosed with typhoid fever and now again this month he is daignosed with typhoid , jaundice and some intestinal infection all together. And somewhere because of all these issues he is feeling depressed and regreting the surgery. So I am just wondering ,where is he lacking? What he can do to enhance his immune system ? Any Expert advice? Thanks in Advance.