I hope some of my reply will help all of you.
Blood in stool, no matter how small, is not an imbalance issue. It's usually an allergy issue and usually it's dairy but it could be something else. There can be blood in their stool that is naked to the human eye and that too is still bad. In fact my doc will send me home with a test kit, I take samples of LO's poop and smear it on a card, then take them to the lab and the lab will test for microscopic blood.
If the problem is dairy it can take weeks with it completely out of your diet before you see improvement. Kellymom says up to 2 weeks but in my own experience it was closer to 6 weeks. There is hidden dairy in a lot things so please make sure you read labels and get a list of ingredients that mean dairy.
Secondly check out the allergies forum and also this thread
which is for moms who have to eliminate foods while bfing.
Now for my own personal experience: My dd was always high needs. Always fussy, crying, etc. She spit up a ton as well and it had some serious distance on it and smelled nasty. I don't think I have ever seen a normal mustardy seedy poop from her. They were always really mucousy and green...it looked like someone sneezed in her diaper. I can't tell you at all how I figured it out but suddenly, when she was about 3 mos old it occurred to me that it was corn that was bothering her. I cut out all corn, and let me tell you that is no easy task, corn is the hardest food to avoid, it has a list of ingredients that mean corn that is 3 pages long. She improved drastically within days (luckily corn doesn't stay in your body like dairy). But the nasty poops were still there. So I decided to take the plunge and I went on a total elimination diet. This was not easy by any means at all. I ate only turkey, lamb, pears, rice, squash, olive oil, salt and pepper. That's it. Nothing else. And I ate only that for almost 2 months before we reached "baseline" with my dd. It was so worth it though. She improved so much!! No more spitting up and although she is still high needs she was SO much happier! I began adding foods back in very slowly and discovered she is allergic to a lot of things. The biggest being corn, dairy, wheat, and eggs. Also she used to react to oats but she has outgrown that one. It's been 6 mos since I started the TED and 7 mos that I've been without corn which means 7 mos since I've eaten anywhere but my own home or eaten anything that came out of a box or a can. It's hard. I've lost over 40 lbs and I wasn't hardly over weight to begin with. It's been worth it though. She is so much happier. Although I do have to say that her poop never changed. But the doc said since she was obviously so much happier and healthier that I shouldn't worry about it so I don't.
Also one other thought: if you had antibiotics in labor or the baby has had antibiotics it could also be a yeast problem. I believe there is some talk about that in the thread I linked above and also in the allergies forum. That requires a different diet.
I hope I was some help and I hope I didn't