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. Symptoms of a severe and sudden (acute) anterior cruciate ligament (ACL) injury include: 1  Feeling or hearing a pop in the knee at the time of injury.2  Sudden instability in the knee. 3  Pain on the outside and back of the knee. 4  Knee swelling within the first few hours of the injury. 5  Limited knee movement because of swelling and/or pain.ther health problems can cause symptoms like those of an ACL injury. They include a bone break or injuries to the knee cushions (menisci) or to other ligaments in the knee. For more information on knee injuries, see: 1  Knee Problems and Injuries.