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.
1 White blood cells in the stool may be caused by inflammation of the intestines, such as ulcerative colitis, or a bacterial infection. 2  Rotaviruses are a common cause of diarrhea in young children. 3  If diarrhea is present, testing may be done to look for rotaviruses in the stool. Stool with a high pH may mean inflammation in the intestine (colitis), cancer, or antibiotic use. 2  Blood in the stool may be caused by bleeding in the digestive tract. 3  White blood cells in the stool may be caused by inflammation of the intestines, such as ulcerative colitis, or a bacterial infection.