My daughter was born in early July of this year (2011) and as of August 14th she's been having stringy bright red blood in her stool off and on. She is exclusively breastfed. The first time I saw the blood I called my pediatrician and took her in for an appointment. The pediatrician noticed 2 anal fissures and told me to send in a poopy diaper a week later to test it for blood. If it comes out positive, she said the blood probably wasn't from the fissures (they'd heal by then I guess?) and that she would put me on an elimination diet.
The test came back positive for blood, so I was told to eliminate all dairy (whey, casein, etc.), soy (soybean oil, lecithin, etc.), nuts, and eggs. 3 weeks later (my daughter's 2 month checkup) we had another test for blood, and it came back negative. I explained to the pediatrician that I had been seeing blood off and on the entire 3 weeks, but she decided that the blood was the result of a food intolerance and that I can now add eggs back to my diet. If a test comes back positive for blood the next week, I must eliminate eggs completely. The pediatrician performed an anal exam on my daughter but didn't give us a clear answer on whether or not she still had fissures at that time. The next bowel movement after that exam had as much blood in it as the first time I saw blood in my daughter's diaper (which was more than any other time since this situation began). I had not yet added eggs back into my diet.
A week later (eating eggs) the test came back positive for blood, so the pediatrician is now saying no eggs at all and the next time we have a negative test result I can add back something else (soy, nuts, or dairy). Just looking at the test results, this conclusion seems reasonable, but at home I am seeing NO change in my daughters bloody diapers from this diet or the addition of eggs. The positive or negative results are simply coincidence. Some days she has a bloody diaper and some days she doesn't.
My daughter has no other symptoms of food intolerance. She's gaining weight beautifully, does not vomit or act like she's in pain, sleeps well, doesn't have any skin rashes, etc. The only symptom is blood in her stool every so often, which is enough to concern me that her pediatrician is missing something.
Your daughter's pediatrician is obviously missing something.I would consult a naturopathic pediatrician. They generally have a better understanding of the digestive system than allopatic doctors; their test are more comprehensive.
Other common food intolerances are fructose intolerance, MSG intolerance and gluten intolerance, so I'm surprised that these foods were not inculded in the elimination diet.
BTW bloody stool from food intolerances is most likely caused by a tear in the anus or excessive wiping from diarrhea. It can also indicate small tears in the mucosa lining the large intestine, so have your daughter checked properly.