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Since there is blood which you can see, it is coming from the lower gut. This can happen in hemorrhoids, rectal polyps, diverticulosis (outpouchings from the bowel wall), inflammatory bowel disease, or dysentery.
In hemorrhoids the blood falls after the stool. In fissures it lines the stools. In all other problems the blood is mixed with stools. There are hemorrhoidal creams available in the market which you can apply. Sit in a tub of warm water for 10 mins at least twice a day. Increase fiber in your diet. Eat lots of fresh fruits, vegetables, oats, porridge etc. Good sources of fiber are fruits, vegetables, and whole grains. In addition you can try bulk stool softener such as psyllium (Metamucil) or methylcellulose (Citrucel).
Since you also have bloating, pain in abdomen you will need to consult a gastroenterologist to rule out inflammatory bowel conditions.
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, Crohnâs disease etc. Irritable bowel syndrome is diagnosed by elimination of other causes. Gluten is a complex protein present in four main grains---wheat, rye, barley and oats. 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.
Crohnâs disease is a difficult entity to diagnose. Along with gut symptoms skin disorders and arthritis too are commonly seen with Crohnâs. 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 does confirm inflammation in the body. Low protein, minerals and iron in blood are the other findings in Crohnâs which may or may not be present. A recent advancement in Crohnâs diagnosis is video capsule endoscopy.
Since a confirmed diagnosis cannot be given on net please discuss these possibilities with your gastroenterologist. Hope this helps. Take care!