Suggest Treatment For Diarrhea And Abdominal Cramps

A 28 year old Caucasian woman with severe diarrhea and abdominal cramping. The diarrhea large in volume of particularly foul odor and yellowish- brown color. Symptoms of and on over the past few years. Has gotten worst over the past week. No fever, no blood in her stool and no recent history of surgery or of travel out of the country. However she has returned from a week-long stay at her friends home in another state. Unmarried without children and currently not pregnant. No history of obstetric or gynecologic illness or eating disorder, and she is currently on no prescription or non-prescription medications. There is no history of colorectal or other cancers or of intestinal disease. Upon exam her abdomen is bloated with diffuse, centrally located tenderness to palpation both above and below the umbilicus. Vital signs were Blood pressure (supine) 120/64, blood pressure (standing) 95/58 with some light-headedness upon araising heart rate (supine) 88bpm, heart rate standing 104bpm. Oral temperature was 99.7, Her weight 115lbs went down from normal weight of 128lbs. Stool sample tested negative for blood. The reminder of her physical exam revealed no abnormal findings.