Definition Increasing pressure behind a fecal impaction can cause the colon to expand and even rupture. Constipation is a term used loosely by lay people, partly due to a misunderstanding of what constitutes normal bowel movement frequency. Many people believe that the norm is a single daily bowel movement. To reach this end, patients may strain at the stool when they think a bowel movement should be imminent, rather than awaiting the defecatory reflex. In actuality, the number of daily bowel movements is highly variable.
Physicians define normal stool frequency as anywhere from three defecations daily to three weekly.
Thus, one of the first things the pharmacist should try to discern is what a patient's normal defecation frequency is. If it was stabilized at three daily for a patient, a reduction to one bowel movement daily might produce hard stools that lead to constipation. On the other hand, if a person's normal frequency is three weekly, two weekly might harden feces so that evacuation is hampered. A study of patients aged 60 and over examined which bowel parameters are used by patients to define constipation. Those most closely correlated with self-reports of constipation were straining at the stool and having hard feces.