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. Find possible causes of blood in stool based on specific factors. Check one or more factors on this page that apply to your symptom. 1  In or on the stool. 2  In toilet bowl or on toilet tissue. 3  Drinking alcohol or caffeine. 4  Eating certain foods. 5  Straining during bowel movements. 6  Drinking more water. 7  Eating certain foods.