Hi.
Thanks for your query.
Noted the history about your Mother who is 83 years old having urge to pas bowel movements frequently, you have consulted the Doctor who said she has stool in bottom and lots of pain also.
The causes of such a problem in an old can be as follows:
Fecolith impaction in the rectum.
Entero-
colitis.
Cancer of the rectum or colon.
IBS that is
irritable bowel syndrome.
I would advise you the following in such a situation:
Clinical evaluation, examination and investigations under the guidance of a
General Surgeon.
X-ray of the abdomen to see for bowel obstruction,
fecal impaction, if present to give her enema to clear the bowel and the problem may be solved.
CT scan of the abdomen and
colonoscopy to see for cancer and to treat accordingly.
Tests of blood, urine and stool.
All these things will lead to the proper diagnosis and give a proper plan of treatment.