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.
Twisting the knee is a common cause of overstretched or torn ligaments of the knee. The knee may give out suddenly when the ACL is torn and there may be a popping sound upon injury. Symptoms of a torn ACL include knee pain, swelling, stiffness, and bruising.