Patient description: A 34 year old man comes to the clinic complaining of dizziness and severe diarrhea since yesterday. He has returned from an international trip few days ago and was living in a camp in Sudan for a month. He developed abdominal pain followed by bloating and nausea as well as loose bowel movements. Soon he was having profuse watery diarrhea without odor. The stool is watery and white but the patient has no fever. Blood pressure is 95/62 lying down and drops to 75/40 standing. The skin turgor has reduced. HR is 110 and he looks ill with dry mucosa. V. cholerae was seen in dark-field microscopy of a fresh stool specimen. The lab study is as bellow: Sodium 137 meq/L Potassium 2 meq/L Chloride 94meq/L CO2 15 meq/L Fecal leukocytes None seen Fecal occult blood Negative

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Constipation Chronic Disease for entry into the study (Performed at screening) Male and females of at least 18 years of age (no upper limit) History of constipation for at least 12 months before screening. Constipation is defined as follows: less than three spontaneous bowel movements per week that result in a feeling of complete evacuation, and one or more of the following At least 25% of the stools are very hard and/or hard stools (Type 1 and/or 2 on the Bristol Stool Form scale)14 Sensation of incomplete evacuation following at least 25% of the bowel movements Straining on at least 25% of the defecations The above are only applicable for spontaneous bowel movements, i.e. not preceded within a period of 24 hours by the intake of a laxative agent or by the use of an enema. Patients who never have spontaneous bowel movements (that is, all bowel movements are preceded by laxatives) are considered constipated and eligible for the study Patients who are able to communicate well with the investigator and to comply with the requirements for the entire study, including the withdrawal period Patients who provide written informed consent before participating in the study after being given a full description of the study  for entry into the study (Performed at screening): Patients meeting one or more of the following should not be included in the study Use of herbs before 2 weeks of study Planned use of disallowed medication With evidence of cathartic colon or a history of laxative abuse With a history of fecal impaction which necessitated surgical intervention Whose chronic constipation, according to the investigator's clinical judgment, is thought to be a result of: bowel surgery, gynecological surgery, neurologic disorders (e.g. aganglionosis, hypoganglionosis, autonomic neuropathy, Parkinson's disease, spinal cord injury or tumor, cerebrovascular accidents, multiple sclerosis), systemic sclerosis, myloidosis, scleroderma, myotonic dystrophy With a diagnosis of megarectum or colon, intestinal pseudo-obstruction, mechanical outlet obstruction, congenital anorectal malformation, rectocele, intestinal carcinoma, inlammatory bowel disease An endoscopic/radiologic bowel evaluation (colonoscopic examination and/or a sigmoidoscopy + barium enema) is required in order to rule out cancer, inflammatory bowel disease or other structural disease. This evaluation must have been performed within the past 5 years. In addition, there should not be history or evidence of weight loss, anemia or rectal bleeding since the evaluation was performed Existence of surgical or medical conditions which interfere with the absorption, distribution, metabolism and excretion of the study medication With hypo or hyper thyroidism (clinically significant abnormal TSH level at screening)