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.
Red Blood in Baby Poop. While your babyâs poop can turn red because of something he or she ate or drank, such as tomatoes or fruit punch, red baby poop can be a sign of blood in the stool. Red blood found in normal poop could be a sign of a milk protein allergy, while red blood in diarrhea could mean your baby has a bacterial infection.