People who are in Coma stage will not be in their senses. So it becomes increasingly difficult for their family members to take care of them. You never know when they pass their stools or urine. Even a nurse , when deployed to take care of the patient will find it extremely difficult to help them pass their urinals. So I suggest a easy way to dispose the wastes by using disposable diapers. Disposablemedicalexpress.com is the site that sells diapers.