In the case of hematochezia, the blood may coat the stool, be mixed in with the stool, or even be passed by itself without any stool at all. Potential causes of black colored stools include: acidified blood (blood from higher in the digestive tract)
The most common symptoms of a meniscus tear are: 1  Knee pain. 2  Swelling of the knee. 3  Tenderness when pressing on the meniscus.  Popping or clicking within the 1  knee. Limited motion of the knee joint.
Symptoms of a bruised knee. Symptoms of a bruised knee include instant pain at the time of injury with bruising which may develop over the following day. The area will be tender to touch and there may be some swelling. The bruising will change color and start to fade after a few days.