Longitudinal Immunophenotyping of Patients With Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD) is a term used to describe disorders that cause long-term inflammation in the digestive tract. Symptoms include stomach pain, diarrhea, and bleeding. Crohn's disease and ulcerative colitis are the 2 main types of IBD. Researchers want to conduct a natural history study to learn more about whether genetic factors can cause IBD; how immune cells contribute to IBD; and how diet, drugs, and disease affect those cells. Objective: To better understand IBD over time. Eligibility: Adults aged 18 to 85 years with Crohn's disease, ulcerative colitis, or another IBD. Their healthy relatives are also needed. Design: Affected participants will have clinic visits every 6 months for 3 years. Once a year, they will have these procedures: A physical exam with blood and stool samples. Ultrasound of the abdomen. A wand will be rolled over the skin. It uses sound waves to capture images of the intestines. Magnetic resonance imaging (MRI) scan. They will lie on a table that slides into a tube. Magnetic fields will capture images of the intestines. Colonoscopy. A long, flexible tube with a video camera will be inserted into the rectum to view the entire colon. Up to 12 tissue samples may be taken. Upper endoscopy, for those with Crohn's disease. A long, thin tube with a camera will be inserted through the mouth and into the first part of the small intestine. Up to 12 small tissue samples may be taken. Questionnaires. Participants will answer questions about their disease and their diet. Midyear visits will include a physical exam, blood and stool collection, ultrasound, and questionnaires Healthy relatives will have 1 blood draw for genetic tests.

NCT Number	NCT07619547
Lead Sponsor	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Conditions	Inflammatory Bowel Disease, Crohn's Disease, Ulcerative Colitis
Enrollment	100 participants
Start Date	2026-08-19
Primary Completion	2036-06-01 (estimated)
Study Completion	2036-06-01 (estimated)
Updated on ClinicalTrials.gov	2026-08-14