I am a 28 year old asian male who has been experiencing a plethora of gastrointestinal issues for probably at least the past 2 years. I've been managing until just recently, when I noticed some dark, tarry stools and prompted a visit to my doctor. I have been having diarrhea and constipation (but mostly diarrhea) for quite some time now. Often it's after eating a greasy meal and sometimes not. I find myself having to use the toilet more frequently after meals, with loose and sometimes thin stools. I don't recall when the last time I actually felt hungry, as I constantly feel bloated after a meal with quite a bit of burping and gas. Over the past year, a few times I've had heart palpitations and elevated blood pressure. Also I felt like I had some heart pain, which went away after a few hours. I've also noticed that at times when trying to defecate, I would have incomplete episodes, trying but with nothing coming out. Also I've noticed small amounts of red blood on the toilet paper after wiping and after taking a picture of my underside with my camera, it appears to be either from hemorrhoids or anal fissures due to visible cuts on my perineum area. Also my anus and perineum has been itchy for some time now, which i have been treating with a corticosteroid cream, but I suspect that it's probably a result from the increased bouts of diarrhea i've been experiencing. I've noticed some weight loss over several months (from about 75 kg to 71-72) but i've been exercising occasionally, and maybe due to my recent slight loss of appetite, i've lost a bit of weight. I've also been fatigued quite a bit (even with 6-7 hours sleep every night). After dinner sometimes, I get overwhelmed with an extreme tiredness. Also i've been driving long distance (12 hours return) almost every weekend to see my girlfriend. My most recent blood tests indicated that my cholesterol was borderline high (5.5) and my B12 levels was borderline low (177). According to my doctor, my liver function tests and Complete Blood Cell Count tests were okay. Roughly 2 years ago, I was treated for appendicitis and had my appendix removed. Also over the past 5 years or so, i've been taking antacids (pepcid ac, and now zantac) prior to drinking alcohol to reduce the effects of flushing. I understand now that prolonged use of antacids may reduce stomach acids, which potentially can reduce my B12 levels due to decreased production of intrinsic factor. I am also not sure if this prolonged use of H2 blockers may have allowed an increase in bacteria inside my stomach and digestive tracts including perhaps the Helicobacter Pylori bacteria. All of the symptoms that I am currently experiencing point to either Stomach or Colon cancer. Also there does not appear to be any family history of either types of cancer and lower risks factor due to my age, I can't help but be nervous due to all the symptoms that line up. My doctor has requested for me to do some additional tests including a FOBT, Hepatitis, Celiac Disease, Coagulation test as well as an appointment with a gastrointestinal surgeon. Can you please help me understand what my body is trying to tell me? I sincerely hope that it's nothing serious.