I am 71 yrs old, I had surg. on my shoulder and had no appetite after this . about 3-4 wks after surg. my stomach started bothering. First smells bothered, I have nausea , taste in my mouth, food doesn t always taste right, just don t feel good. I have had diarrhea at times usually have to go after eating. I had 5 different tests on my stool and they were all neg.