In bright light, the pupil constricts to reduce the amount of light entering the eye. In dark or dim light, the pupil dilates to allow more light into the eye to improve vision. Normal pupil size tends to range between 2.0 and 5.0 millimeters, depending on the lighting. The younger you are, the larger your pupils tend to be.
Fecal incontinence is commonly caused by altered bowel habits (generally diarrhea, but also constipation) and conditions that affect the ability of the rectum and anus to hold stool. The sphincter muscles become weaker as you grow older.
Video Transcript. Douglas A. Drossman, MD: Fecal incontinence is a condition where the muscle down in the sphincter area, the rectal, the anal rectal sphincter, the muscle that controls the passage of the bowel movement might be getting a little bit weak. And when that occurs, there can be leakage.