Hi, I have been having bad upper stomach pain on the left side. It comes in like waves and it feels as if my mid chest and heart tighten up for about 3 seconds then it goes away. It s scary and happens at least once a minute. Also I have not been able to use the bathroom regularly, number 2 that is. Some other symptoms i have are loss of appetite , fever, cough , and fatigue . These symptoms vary from different things, do you have any clue what this might be?