This study intends to select patients with confirmed moderate-to-severe Crohn's disease (CD) and obstructive symptoms of intestinal stenosis, who have clear evidence of lumen stenosis caused by the disease itself through radiography or endoscopy. After the informed consent of the patients, comprehensive drug therapy with Guselkumab or Ustekinumab as the mainstay was performed. The basic information and medical history of the patients were collected, and the treatment process of the patients was followed up and recorded, and the drug regimen was adjusted according to the physician's experience and judgment. At different follow-up time points, blood, feces, tissue and other specimens of patients were collected according to the situation, and gastrointestinal endoscopy, imaging examination, laboratory index examination, self-assessment of subjects' symptoms, and nutritional risk screening were performed on the patients. This study evaluated the CD disease activity, obstructive symptoms, and radiographic or endoscopic remission in patients at different follow-up time points, and comprehensively evaluated the efficacy of ustekinumab in relieving stenotic CD and its related factors.

Inclusion Criteria:

• Confirmed patients with moderate-to-severe Crohn's disease (CD), aged 18 to 80 years, receiving treatment with Guselkumab or Ustekinumab.

• Presence of obstructive symptoms consistent with chronic or subacute intestinal obstruction within the past 8 weeks, with confirmed postprandial abdominal pain attributable to strictures, with the exclusion of: ① mild to moderate pain (postprandial abdominal pain or abdominal pain exacerbated by diet, ameliorated with abdominal bowel sounds) without nausea, vomiting or abdominal colic; ② dietary restrictions unrelated to abdominal pain.

• Evidence of definite luminal strictures caused by the disease itself confirmed by radiographic imaging or endoscopic examination, i.e., meeting any of the following criteria:

  1. Enteric computed tomography (CT): Presence of intestinal strictures on enteric CT, with two of the three following findings at the stricture site compared with the adjacent proximal bowel: ① a >50% reduction in luminal diameter; ② a >25% increase in bowel wall thickness; ③ pre-stenotic dilation >2.5 cm.
  2. Endoscopic examination: Intestinal strictures that are impassable to the endoscope.

Exclusion Criteria:

• Patients with severe disease requiring emergency surgery or endoscopic therapeutic intervention, or those judged by the attending clinician to need a switch of medication or elective surgery within 2 months, such as those with acute severe intestinal obstruction, perforation, intra-abdominal abscess, intra-abdominal adhesion, and other conditions leading to obstruction, hemorrhage, infection, etc.
• Intestinal obstruction, intra-abdominal abscess, isolated intestinal stricture and other lesions secondary to surgery.
• Patients who have received definitive therapeutic interventions for strictures within the past 6 months, such as endoscopic balloon dilation, stricture incision, intestinal stricture plasty, surgical/manual anal dilatation, etc.
• Severe patients who remain unable to take oral intake despite enteral nutrition (EN) administration for more than 2 months.
• Patients who have used Guselkumab (GUS), Ustekinumab (UST) or other IL-23 antagonists within the past 12 months; or those with contraindications to GUS/UST, or intolerance to the study medications due to other causes (e.g., allergy to IL-23 antagonists).
• Patients with contraindications to small intestinal computed tomography (CT), such as contrast media allergy.
• Patients with relative contraindications to biological agents, such as active tuberculosis with a positive chest X-ray for pulmonary tuberculosis or a strongly positive tuberculin skin test; a history of myocardial infarction, heart failure or demyelinating neurological diseases within the past 5 years.
• Patients currently suffering from solid tumors, with a past history of lymphoma or melanoma, or undergoing chemotherapy or radiotherapy.
• Patients complicated with intestinal dysplasia (e.g., diagnosed with short bowel syndrome), colostomy or colorectal neoplasms.
• Patients complicated with active massive gastrointestinal hemorrhage, severe hepatic and renal dysfunction, active bacterial or viral infection, shock, as well as intractable vomiting and severe malabsorption syndrome.
• Pregnant or lactating patients.
• Patients with severe hemodynamic and vital sign instability, or those with rapidly progressive or end-stage diseases.
• Patients with psychiatric disorders, or those with insufficient educational level to fully understand the study content or unable to cooperate with the completion of the study.

Patients who will initially receive Guselkumab or Ustekinumab for the treatment of stricturing Crohn's disease