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.
My baby has blood in her diaper. The same maternal hormones that cause swollen testicles and labia are also responsible for the bloody vaginal discharge that newborn girls sometimes have. Don't worry if you see a small smudge of blood or bit of staining on your baby's diaper in the first weeks of life.