Hi
Welcome to the MedHelp forum!
Since there is blood which you can see, it is coming from the lower gut. This can happen in hemorrhoids, rectal polyps, colon polyps, diverticulosis (outpouchings from the bowel wall), inflammatory bowel disease (IBS, Crohn's, Celiac, ulceative colitis), or dysentery (ruled out in your case).
It would be wise to get a colonoscopy and also consult a gastroenterologist.
A number of times a gastroenterologist is able to diagnose these conditions by clinical examination and detailed medical history. At other times a few tests are conducted. Blood tests to rule out anemia, stool test to look for white blood cells, sigmoidoscopy, colonoscopy etc are used to diagnose ulcerative colitis. Braium meal and follow through, endoscopy etc are done to rule out GERD, Crohn’s disease etc. Irritable bowel syndrome is diagnosed by elimination of other causes. If you have gluten intolerance, then you probably have celiac disease or Non Celiac gluten sensitivity. There are blood tests called celiac test to detect gluten intolerance.
Crohn’s disease is a difficult entity to diagnose. Along with gut symptoms skin disorders and arthritis too are commonly seen with Crohn’s. An upper GI series using barium dye is done to see the condition of small intestines. The degree of involvement of the large and small intestine may vary from person to person. A biopsy is the most confirmatory. An elevated ESR, low protein, minerals and iron in blood are the other findings in Crohn’s which may or may not be present. A recent advancement in Crohn’s diagnosis is video capsule endoscopy.
Since I cannot examine you and know other related conditions you may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP to run tests and examination and also a gastroenetrologist to clinch a diagnosis.
Take care!
Well if you are bleeding from your rectum, I'd ask for a colonoscopy. You're 50 so you should have one anyways.