This study aims to assess elemental impurities level after dministration of dioctahedral smectite in subjects with functional diarrhea or irritable bowel syndrome with predominant diarrhea. Male or female subjects aged between 19 and 60 years will participate in the study. The study design is an opne-label, randomized, multiple dose paraller study. The patients were randomly assigned to DWJ1230 or DWB2001. It is intended that a total of 60 subjects will be enrolled to ensure that at least 24 subjects will complete the study.

Inclusion Criteria:

• Subjects with chronic functional Diarrhea. (included Irritable Bowel Syndrome with perdominant diarrhea(IBS-D)).
• Male or Female subjects aged between 19 and 60 years at screening.
• Body Mass Index(BMI) between 18 and 27kg/m2 in male, 17 and 26kg/m2 in female. ※ BMI (kg/m2) = body weight (kg)/[height (m)]2
• Subjects who voluntarily decided to participate in the study and provided written consent to follow precautions after receiving a sufficient explanation on this study and fully understanding the information.

Exclusion Criteria:

• No history or clinically significant symptoms or severe disease, including cardiac, neurological, pulmonary, hepatic, biliary, gastrointestinal, endocrinologic, or renal disorders, or cancer.
• Identified or strongly suspected organic cause to diarrhea.
• Celiac disease or Intestinal malabsorption, Unspecified intestinal malabsorption.
• History of any serious adverse reaction or adverse event or hypersensitivity to any component of investigational product.
• Constipation, Iron deficiency anaemia, Hypocalcaemia, Osteoporosis.
• Known domestic, leisure or professional exposure to elemental impurities.
• Women who are breastfeeding or are planning to become pregnant during the study.
• Positive pregnancy test at screening.
• Presence of clinically significant physical, laboratory, vital signs, or ECG findings.
• Blood lead level > 3.3 μg/dL(=33.0 μg/L) at screening.
• galactose intolerance, fructose intolerance, Lapp lactase deficiency, sucurase-isomaltase deficiency, glucose-galactose malabsorption.
• Receipt of any investigational agent or study drug within 4 weeks prior to screening.
• Patients with history of alcohol or drug abuse.
• Subjects who donated whole blood within 2 months, donated blood components within 1 month.
• Subjects who have participated and taken investigational drug within 1 month prior to study drug administration.
• Subjects who the investigator considers inappropriate for the study due to other reasons.