What are the steps to conduct an Upper Gastrointestinal Series (UGIS) with Small Intestine Series (SIS)?

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Steps to Conduct an Upper Gastrointestinal Series (UGIS) With Small Intestine Series (SIS)

The most effective approach to conducting an Upper Gastrointestinal Series with Small Intestine Series requires proper patient preparation, standardized contrast administration, and systematic imaging to maximize diagnostic yield while minimizing patient discomfort.

Patient Preparation

  • Fasting requirements: Instruct patient to fast for 6 hours for solids and 1 hour for clear liquids prior to the procedure to ensure good visualization while minimizing patient discomfort 1
  • Medication review: Document any medications that may affect GI motility
  • Contraindications assessment: Check for complete esophageal or gastric obstruction, which would contraindicate barium administration 2
  • Patient positioning: Position patient upright on fluoroscopy table initially

Equipment and Materials

  • Fluoroscopy unit with recording capability
  • Barium sulfate contrast medium (or water-soluble contrast if aspiration risk or perforation suspected)
  • Nasogastric tube (if needed for administration)
  • Cups and straws for oral administration
  • Compression paddles
  • Protective equipment for staff

Procedural Steps

1. Initial Assessment and Setup

  • Confirm patient identity and procedure indication
  • Explain procedure to patient
  • Obtain preliminary scout radiograph to assess for abnormal gas patterns or calcifications

2. Contrast Administration

  • Administer 5 cc/kg of barium sulfate orally (or via nasogastric tube if necessary) 3
  • Have patient drink in upright position while fluoroscopically observing the passage of contrast

3. Esophageal Evaluation

  • Observe first swallows in real-time under fluoroscopy
  • Document esophageal motility, mucosal pattern, and presence of reflux
  • Take spot images of any abnormalities

4. Gastric Evaluation

  • Assess gastric filling, mucosal pattern, and peristalsis
  • Obtain images in multiple projections (AP, lateral, oblique)
  • Evaluate gastroesophageal junction for reflux
  • Document gastric emptying pattern

5. Duodenal Evaluation

  • Position patient to visualize duodenal bulb and C-loop
  • Critical step: Clearly identify the duodenojejunal junction (DJJ) to rule out malrotation 3
  • Take images immediately and at 1 minute after contrast reaches duodenum

6. Small Intestine Series

  • Continue observation as contrast progresses through small bowel
  • Take sequential images at 5 minutes, 1 hour, and 2 hours 3
  • Use compression paddles as needed to separate overlapping bowel loops
  • Document transit time through jejunum and ileum
  • Assess for filling defects, strictures, or abnormal mucosal patterns

7. Terminal Ileum and Ileocecal Valve

  • Continue imaging until contrast reaches the terminal ileum and ileocecal valve
  • Document passage of contrast into the cecum

Post-Procedure Management

  • Provide patient with instructions to increase fluid intake to prevent barium impaction
  • Consider mild laxative (milk of magnesia or lactulose) to prevent constipation 2
  • Document findings in a standardized report including:
    • Extent of examination
    • Any abnormal findings
    • Documentation of samples taken (if applicable)
    • Proposed management plan

Special Considerations

  • For pediatric patients: Adjust contrast volume based on weight and consider bedside examination for NICU patients 3
  • For suspected aspiration risk: Consider water-soluble contrast instead of barium 2
  • For post-surgical patients: Modify protocol based on altered anatomy, particularly for post-gastrojejunostomy patients 4, 5

Common Pitfalls to Avoid

  • Inadequate patient preparation leading to poor visualization
  • Failure to clearly identify the duodenojejunal junction, which is critical for diagnosing malrotation
  • Premature termination of the study before contrast reaches terminal ileum
  • Overreliance on UGIS for diagnosing gastroesophageal reflux, as it has limited sensitivity and specificity (31-86% and 21-83% respectively) 6
  • Using barium in cases of suspected perforation (use water-soluble contrast instead)

By following these systematic steps, the UGIS with SIS can effectively evaluate the upper gastrointestinal tract anatomy and function while ensuring patient safety and comfort.

References

Guideline

Diagnostic Approach for Post-Gastrojejunostomy Patients

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Selective, versus routine, upper gastrointestinal series leads to equal morbidity and reduced hospital stay in laparoscopic gastric bypass patients.

Surgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery, 2007

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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