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.
Blood in Baby's Stool. Babies can sometimes have blood in their stool that is caused by food allergies, a small anal tear or fissure, or even a temporary case of lactose intolerance. It might even be a drop of blood that came from a cracked nipple, which the baby then passed through his system.
Blood in stool is a hint that bleeding is present in the digestive tract. The bleeding is usually described either as dark in color or bright red blood on toilet tissue or stool. But in some occasions, the presence of blood can only be determined by a procedure known as fecal occult blood test. The causes of bloody stool can also be determined using several other diagnostic methods.