Fecal microbiome of donor and recipient will be analyzed before and after fecal microbiota transplantation in IBD patients.

Fecal microbiota transplantation will be performed to the IBD patients, and microbial analysis will be done for donor and recipient feces. Fecal microbiota transplantation will be done twice via colonoscopy, with one month of duration. During the early stage of Fecal microbiota transplantation, recipient feces will be analyzed for the intestinal microbiota frequently.

Clinical outcome will be assessed 1month, 2month, 6month, and 1 year after the transplantation.

Relevance of intestinal microbial change and clinical outcome after transplantation and factors associated with successful clinical outcome will be investigated.

Inclusion Criteria:

• 7 years old to 80 years old at start of trial
• Inflammatory bowel disease such as ulcerative colitis, Crohn's disease, and Behcet's colitis
• Patients who do not respond to the conventional treatments or who do not wish/not able to use one.
• Patients who agree to participate in the trial after thorough explanation
• Evidence of active disease

Exclusion Criteria:

• Patients whose CRP<8, calprotectin<200, and mucosal healing endoscopically (who are in stable state)

• Patients whose symptom is due to other disease than IBD

  _Patients with immunosuppressive disease

• Patients who are clinically unstable such as massive hemorrhage or perforation

• Patients with toxic megacolon, paralytic ileus, or symptomatic intestinal obstruction

• Absolute neutrophil count (ANC) <1.5 *10^9/L (1500/mm3)

• Pregnant or under breast feeding

• Patients enrolled in other clinical trials