I suppose your mother is drinking less water, which might be the root cause of hard stool. Now hard stool might have caused anal fissure, a painful condition. Less water intake might be the reason for frequent small quantity painful urination.

Hi Your mother has multiple complaints. To simplify I will sequence them in order of priority. First... Frequent urination is suggestive of bladder urgency which may be due to infection or sometimes neuropathic. Need to rule out incontinence also. Second... Painful defecation may be related to anal fissure. Last... Abdominal pain may be due to gastritis or pain from pancreas or gall bladder.. Exact cause needs history and evaluation