Imo blood in stool for those who are mercury toxic is probably due to parasites or a vitamin k deficiency. Did you do a parasite cleanse recently? If not, I suggest that you do one after the blood in the stool stops(some of the cleansing herbs have anticoagulant properties). Imo it would also be a good idea to take vitamin k 200 mcg a day until the bleeding stops, then 100 mcg a day maintenance. If you are taking vitamin e, then stop taking it. Vitamin e is a very potent anticoagulant. I had nosebleeds while on high doses of vitamin e. Vitamin c, garlic, cinnamon, and other herbs are also anticoagulants, but more mild than vitamin e. If you are taking large doses of vitamin c(more than a gram a day) then imo you should cut this back to a gram a day until the blood in the stool stops. Imo you should also stop using cinnamon and garlic until the bleeding stops. You don't want to lose too much blood, as those who are mercury toxic tend to already be anemic, especially if they are female.

It would be a good idea to go on a very low carbohydrate diet, cutting out sugar, alcohol, wheat, fruit, and starchy vegetables(potatoes, sweet potatoes, peas, etc.). Carbohydrates feed candida and parasites. Eat nuts, meat, eggs(if you can tolerate them), and low carbohydrate vegetables. A herbal parasite cleanse contains herbs that also kill candida. Wormwood(which most herbal parasite cleanses contain, is said to be the most potent killer of candida(use as recommended though, as overuse can be toxic)).

I also like the idea of eating small amounts(3-5 ounces) of low mercury fatty fish once or twice a week(such as sardines, herring, or salmon), though some here are afraid of the tiny amount of mercury in even small amounts of low mercury fish. Some may suggest refrigerated fish oil supplements(not on the shelf room temperature capsules. This should be tested to be mercury free).Wait until the bleeding stops to do this, as even fish fats are anticoagulants.

http://www.gotmercury.org/article.php?list=type&type=75

You didn't mention how severe the blood in the stool is. If it is very severe, then you need immediate medical attention. If it is not severe, then follow my advice above. I also forgot to mention that you should not take aspirin, ibuprofen, or aceteminofen, as these have anticoagulant properties, so if you are taking any of them then stop it. I assume that you are not taking any prescription blood thinners, and if you are then consult with your doctor ASAP. I also assume that if you are taking any prescription drugs you already did a Google search with the drug name and the word anticoagulant, to make sure that none of those have an anticoagulant effect.