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.
The most common causes of chronic incontinence include: 1  Overactive bladder muscles. 2  Weakened pelvic floor muscles. 3  For some men, an enlarged prostate, or benign prostatic hyperplasia (BPH) 4  Nerve damage that affects bladder control. 5  Interstitial cystitis (chronic bladder inflammation) or other bladder conditions.