Inflammatory bowel disease(IBD) is a chronic inflammatory condition for gastrointestinal tract.

Regarding its pathogenesis, there has been numerous studies to reveal the complex association between genetic and environmental factors.

In Korea, the incidence of IBD is growing rapidly but genetic studies solely including patients with Korean descent were not sufficient enough.

Therefore, the investigators planned to conduct genetic and fecal microbial analysis for the 60 individuals from 30 Korean IBD families to find out the pathogenesis of IBD.

Under the hypothesis that more risk variants will be observed among the familial IBD patient than in IBD patients without any other affected family members, the investigators designed genetic and fecal microbiome analysis for 60 patients form 30 families.

After extracting the DNA from blood samples, whole genome sequencing will be performed and data will be comprared with the previously reported variances. Novel variances or incidence of specific variances will be measured.

Genome-wide single nucleotide polymorphism array using Immunochip will be performed to search common genetic variants and to calculate genetic risk score of IBD.

In this study, fecal microbiome is a surrogate marker for the enviromental aspect of pathogenesis of IBD. The investigators assumed that family members are sharing similar mode of lifestyle therefore we're presumed that their fecal microbial composition is alike.

Comparing genetic and microbial datas altogether with the data from unaffected family member(Healthy internal control), investigators expecting to explain the genetic and enviromental aspect of IBD pathogenesis.

Inclusion Criteria:

• 60 individuals from 30 families of Crohn's disease or ulcerative colitis.
• Unaffected 30 individuals from each family as healthy internal control.

Exclusion Criteria:

• Person with history of using antibiotics or probiotics within previous 4 weeks.

The investigators are planned to study family members with IBD(Crohn's disease or ulcerative colitis).

They are all Koreal descent and study candidates are two patients from each 30 families. As a healthy internal control, another family member without IBD history will be also enrolled.

After publishing the results, any data sharing request from other researchers will be positively considered.

But extent of sharing is not decided yet.