Exclusive Enteral Nutrition Therapy for Active and Complicated Crohn's Disease (EEN-CD)

Effectiveness and Safety of Exclusive Enteral Nutrition in Adults With Active and Complicated Crohn's Disease: A Single-Center Prospective Cohort Study

The goal of this observational study is to evaluate the effectiveness and safety of exclusive enteral nutrition (EEN) in adults with active Crohn's disease (CD), particularly in patients with complicated disease such as stricturing disease, enteric fistula, and intra-abdominal abscess. The main questions it aims to answer are:

• What is the clinical remission rate at Week 12 in adults with active CD treated with EEN?
• How does EEN affect clinical response, endoscopic outcomes, inflammatory markers, nutritional status, BMI, and safety during follow-up?

Participants will:

• start EEN at baseline and be followed through Week 12;
• receive EEN as the main treatment approach during the study period;
• complete clinical, laboratory, nutritional, and safety assessments at prespecified follow-up visits;
• undergo endoscopic assessment when endoscopy is performed as part of routine care; and
• if clinically indicated, some participants with large intra-abdominal abscesses may receive percutaneous drainage and necessary antibiotic treatment.

Study Overview

• Status: Recruiting
• Conditions: Crohn's Disease
• Intervention / Treatment: Dietary supplement: Exclusive Enteral Nutrition

Detailed Description

This is a single-center, prospective observational cohort study in adults with active Crohn's disease (CD) who are treated with exclusive enteral nutrition (EEN) during the study period. The study is designed to evaluate the effectiveness and safety of EEN in adult patients with active CD, with a focus on patients with complicated disease, including stricturing disease, enteric fistula, and intra-abdominal abscess.

Eligible participants will be enrolled at the time EEN is initiated (baseline) and followed through Week 12. EEN will serve as the main treatment approach during the study period. In general, no other therapeutic medications for CD will be used. However, for some participants with large intra-abdominal abscesses, percutaneous drainage and necessary antibiotic treatment may be provided when clinically indicated. EEN-related management, including formula type, administration route, caloric targets, and duration, will be recorded.

The primary observation time point is Week 12. The primary endpoint is the clinical remission rate at Week 12. Secondary endpoints include the clinical response rate, endoscopic remission rate, endoscopic response rate, mucosal healing rate, proportion of participants achieving normalization of inflammatory markers, and improvement in body mass index (BMI). Endoscopic outcomes will be assessed when endoscopy is performed as part of routine care. Clinical, laboratory, nutritional, and safety assessments will be collected at prespecified follow-up visits.

Exploratory endpoints include longitudinal changes in the gut microbiome, metabolomic profiles, transcriptomic features, and candidate molecular biomarkers, as well as their associations with clinical and nutritional improvement after EEN treatment.

• Study Type: Observational
• Enrollment (Estimated): 300

Contacts and Locations

• Study Contact: Name: Wei Wang, MD; Phone Number: 86-18702046420; Email: wangw239@mail.sysu.edu.cn

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510000
      • Recruiting
      • The Sixth Affiliated hospital, Sun Yat-sen University
      • Contact: Wang, MD; Email: wangw239@mail.sysu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients (≥18 years) with active Crohn's disease treated at a single center who initiate exclusive enteral nutrition (EEN) as the sole induction therapy and are followed for 12 weeks. The study population primarily includes patients with malnutrition or nutritional risk, and many have complicated disease with intestinal fistula, stricture, and/or intra-abdominal abscess.

Description

Inclusion Criteria:

1. Age ≥18 years.
2. Diagnosis of Crohn's disease established on the basis of overall clinical assessment, including compatible clinical history and standard endoscopic, histologic, and/or radiologic findings, as determined by the treating physician. Histologic confirmation at baseline is not required if endoscopy or biopsy is not feasible or clinically inappropriate because of severe disease, poor nutritional status, or intra-abdominal abscess/sepsis.
3. Active Crohn's disease at baseline, as determined by the treating physician.
4. Willingness to initiate and receive exclusive enteral nutrition (EEN) as the sole induction therapy as part of physician-directed routine care.
5. Presence of malnutrition or nutritional risk and clinical indication for EEN.
6. Patients with intestinal complications, including enteric fistula, intestinal stricture, and/or intra-abdominal abscess, are eligible if considered appropriate for EEN-based management by the treating physician.
7. Ability and willingness to provide written informed consent and to comply with study assessments and follow-up for 12 weeks.

Optional clarifying note:

In participants without histologic confirmation at baseline, the diagnosis may be further confirmed during follow-up when clinically feasible, including by endoscopic biopsy or surgical pathology.

Exclusion Criteria

1. Any absolute contraindication to enteral nutrition, including but not limited to gastrointestinal perforation, uncontrolled gastrointestinal bleeding, severe hemodynamic instability/shock, or other conditions where enteral feeding is not clinically appropriate.
2. Immediate need for emergency surgery at baseline.
3. Inability or unwillingness to receive EEN as the sole induction therapy at baseline.
4. Any condition that, in the investigator's opinion, would make participation unsafe or would substantially interfere with study assessments or follow-up.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

EEN Cohort; Adults (≥18 years) with active Crohn's disease receiving exclusive enteral nutrition (EEN) will be enrolled and followed for 12 weeks. The cohort will mainly include patients with complicated disease, including stricturing disease, enteric fistula, and intra-abdominal abscess. EEN regimen details, adherence, clinical outcomes, inflammatory and nutritional parameters, endoscopic outcomes when available, and safety will be assessed during follow-up.

Dietary supplement: Exclusive Enteral Nutrition; Exclusive enteral nutrition (EEN) consists of a nutritionally complete enteral formula used as the sole source of nutrition during the treatment period, without regular solid food intake except for water and protocol-permitted fluids. Caloric intake is individualized according to body weight, nutritional status, and clinical requirements. EEN is administered to induce disease remission and improve nutritional and inflammatory status in adults with active Crohn's disease, including those with complicated disease such as intestinal strictures or enteric fistulas.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical remission	Proportion of participants achieving clinical remission at Week 12, defined as CDAI < 150.	Baseline to Week 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical response rate	Proportion of participants achieving clinical response at Week 12, defined as a decrease in Crohn's Disease Activity Index (CDAI) of at least 100 points from baseline.	Baseline to Week 12
Endoscopic remission rate	Proportion of participants achieving endoscopic remission at Week 12, defined as a Simple Endoscopic Score for Crohn's Disease (SES-CD) < 4.	Baseline to Week 12
Endoscopic response rate	Proportion of participants achieving endoscopic response at Week 12, defined as a reduction of at least 50% in the Simple Endoscopic Score for Crohn's Disease (SES-CD) from baseline.	Baseline to Week 12
Mucosal healing rate	Proportion of participants achieving mucosal healing at Week 12, defined as a Simple Endoscopic Score for Crohn's Disease (SES-CD) < 3.	Baseline to Week 12
Fecal calprotectin normalization rate	Proportion of participants achieving normalization of fecal calprotectin (FC) at Week 12, defined as FC ≤ 250 μg/g.	Baseline to Week 12
CRP normalization rate	Proportion of participants achieving normalization of C-reactive protein (CRP) at Week 12, defined as CRP within the normal range according to local laboratory standards.	Baseline to Week 12
Improvement in body mass index	Proportion of participants achieving improvement in body mass index (BMI) at Week 12, defined as an increase from baseline.	Baseline to Week 12
Bowel ultrasound response rate	Proportion of participants achieving bowel ultrasound response at Week 12, defined as a reduction in bowel wall thickness and/or a decrease in bowel wall vascularity (Limberg score) compared with baseline.	Baseline to Week 12
Radiologic response rate on cross-sectional imaging	Proportion of participants achieving radiologic response at Week 12, assessed primarily by computed tomography enterography (CTE) and, when available, magnetic resonance enterography (MRE), defined as unequivocal improvement from baseline in active transmural inflammatory findings on cross-sectional imaging, including reduction in bowel wall thickening, mural hyperenhancement, mural stratification and/or mural edema, comb sign, perienteric inflammatory change, and penetrating inflammatory complications, with no evidence of radiologic progression. In participants undergoing MRE, radiologic response may additionally be defined as a MaRIA score <11 or an improvement of at least 25% from baseline.	Baseline to Week 12
Radiologic remission rate on cross-sectional imaging	Proportion of participants achieving radiologic remission at Week 12, assessed primarily by CTE and, when available, MRE, defined as minimal or absent active transmural inflammatory findings on cross-sectional imaging, including absence or near-complete resolution of mural hyperenhancement, mural stratification and/or mural edema, comb sign, and perienteric inflammatory change, without radiologic progression or new penetrating inflammatory complications. In participants undergoing MRE, radiologic remission may additionally be defined as a MaRIA score <7.	Baseline to Week 12
Stricture-related imaging response rate	Proportion of participants with stricturing Crohn's disease achieving stricture-related imaging response at Week 12, assessed by cross-sectional imaging (CTE and/or MRE), defined as: ≥25% reduction in bowel wall thickness or stricture length compared with baseline, and/or; ≥25% reduction in prestenotic dilation, without evidence of radiologic progression.	Baseline to Week 12
Complete stricture resolution rate on cross-sectional imaging	Proportion of participants with stricturing Crohn's disease achieving complete stricture resolution at Week 12, assessed by cross-sectional imaging (CTE and/or MRE), defined as: bowel wall thickness ≤3 mm,; normal luminal diameter without residual narrowing, and; resolution of prestenotic dilation (<3 cm).	Baseline to Week 12
Need for rescue intervention / surgery	Proportion of participants experiencing any rescue intervention at Week 12, defined as the occurrence of unplanned hospitalization, escalation of medical therapy, endoscopic intervention, drainage procedure, or surgery after treatment initiation. Planned baseline procedures performed before or at treatment initiation according to standard clinical management will not be counted as outcome events.	Baseline to Week 12

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Integrated microbiome, metabolomic, and transcriptomic changes during exclusive enteral nutrition treatment	Changes from baseline in microbiome composition, metabolomic profiles, and transcriptomic expression at Weeks 4, 8, and 12 during exclusive enteral nutrition treatment, assessed using stool, blood, and intestinal mucosal biopsy samples when available.	Baseline, Week 4, Week 8, and Week 12; biopsy-based transcriptomic analyses at Baseline and Week 12 when available

Collaborators and Investigators

• Sponsor: Sixth Affiliated Hospital, Sun Yat-sen University

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2020
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: March 22, 2026
• First Submitted That Met QC Criteria: March 26, 2026
• First Posted (Actual): March 31, 2026

Study Record Updates

• Last Update Posted (Actual): May 19, 2026
• Last Update Submitted That Met QC Criteria: May 15, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: intestinal stricture; enteric fistula; exclusive enteral nutrition; active Crohn's disease; intra-abdominal abscess
• Additional Relevant MeSH Terms: Intestinal Diseases; Infections; Digestive System Diseases; Gastrointestinal Diseases; Gastroenteritis; Inflammatory Bowel Diseases; Suppuration; Abscess; Crohn Disease; Abdominal Abscess
• Other Study ID Numbers: 2024ZSLYEC-204

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because this is a single-center study involving detailed clinical, imaging, endoscopic, surgical, and pathology data from patients with complicated Crohn's disease, and there is a potential risk of participant re-identification despite de-identification. Data sharing is also subject to local ethics approval, institutional policy, and participant consent.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No