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.
Here are just a few reasons why your baby may have blood in his stool: 1  An anal fissure, which is a small anal tear often caused by passing a hard stool. 2  A food allergy. 3  Maternal blood from delivery or from cracked, sore nipples.  An intestinal 1  infection. An intestinal disorder, such as colitis or intussusception.
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.