Hi. Thanks for your query. Noted the history about your 70 years old wife, who can not hold her stool at night. This means she can hold in the morning or the day. The causes can be lax anal sphincters, some sort of amnesia or something to do with psychology. This is so because there is control in the day when she is awake. Well, I would advise you the following: Take her to the Senior General Surgeon. Per-rectal digital examination and proctoscopy can find the cause, the laxity or any other problems related to the anus or rectum. The treatment will depend upon the cause. If there is no local cause, obviously the problem may be psychological and needs treatment accordingly.