Concentric contractions: A concentric contraction is a type of muscle contraction where the length of the muscles shorten while undergoing tension. For example, when you pick up a curl bar and perform a biceps curl, the length of your biceps muscles shorten.
Causes of Blood in Stool. 1  Anal Fissure. If no diarrhea, most of these children have a small tear in the anus. 2  Strep Skin Infection. A Strep skin infection around the anus can also cause blood-streaked stools. 3  Bacterial Diarrhea. If also has bloody diarrhea, a gut bacterial infection may be the cause.  Red, but not Blood.
There are many possible causes of blood in the catâs feces, some of which include: Parasitic infection (cryptosporidium, intestinal worms) Cryptosporidium causes inflammation which leads to bleeding, parasitic worms such as hookworm or roundworms suck the blood from the intestinal wall, resulting in blood in the stool.