Hi .. Thanks for contacting HCM for health query.. I really understand the concern behind your enquiry. Your sister is so so much constipated she had to go to emergency department..oh. problem is severe only. If I had a patient like this in my outpatient department I would first relieve her by an enema.,then because of the long duration of such a severe constipation I will investigate the cause for it and give her a stool softener like lactulose. You need to take her a doctor who will guide you to undergo investigations like thyroid,motion complete,ultrasound scan abdomen etc and he will prescribe you stool softener . Meanwhile as a remedy at home give her plenty of fibrous food,include probiotics like yogurt. Hope our suggestion helps. Take care