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.
1 Fecal impaction is a large mass of dry hard stool that gets stuck in the rectum-it is literally so hard that it cannot come out. 2  Rectal cancer-tumors that develop within the rectum can cause bowel incontinence. 3  Rectal prolapse-if the rectum drops down into the anus, bowel incontinence can occur.