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 osteoarthritis of the knee may include: 1  pain that increases when you are active, but gets a little better with rest. 2  swelling. 3  feeling of warmth in the joint. 4  stiffness in the knee, especially in the morning or when you have been sitting for a while.