There's no hemoglobinuria in EVH because the RBCs are broken down extravascularly by macrophages and their hemoglobin is never free in the plasma. In contrast to IVH where RBCs spill their hemoglobin directly into the blood.
In EVH essentially all of the hemoglobin is going to be broken down into bilirubin. You overwhelm the hepatocytes who break it down and you get excess unconjugated bilirubin, as well as somewhat elevated direct bilirubin and excess urobilinogen. However, the back up is really at the unconjugated bilirubin level and you don't get very high direct bilirubin like you would see with a defect in secretion or obstruction of the bile duct.
The reason you don't have jaundice but do have excess urobilinogen in IVH is that you aren't overwhelming the hepatocytes like you are in EVH since much of the hemoglobin released is going to be peed out. However, you will still be supplying some of the hemoglobin released intrascuarly in IVH to the liver and as a result, you will be increasing bilirubin production but physiologically your body can handle increasing production a bit and your labs will be normal. The enterohepatic recycling system is not overwhelmed, and the direct bilirubin that reaches the gut will be partially converted to urobilinogen. Just like in normal physio some of that urobilinogen will be recycled, but you now have more of it entering the bloodstream where it is free to be peed out and you will see that in urine urobilinogen levels.
