Hi. Thanks for your query. Noted the history and understood the concerns. 40 weeks and 2 days is already a late pregnancy and there is no point in waiting at home with such severe diarrhea, pain and vomiting as this can definitely harm the baby as you may develop septicemia, dehydration and so on. I would advise you the following in such a situation: Urgent admission to the hospital and be seen by the Obstetrician and a Physician for clinical evaluation, examination and investigations of the stool, blood, ultrasonography and get started with proper medications, intravenous fluids and electrolyte. You will need a close watch by the Nurse and the team of Doctors for your safely and well being of the child to be born. Do not try anything at home.