Stool Impaction

Preliminary Diagnosis: Stool impaction

I. What imaging technique is first-line for this diagnosis

• Plain radiography (kidneys, ureters and bladder, KUB)

II. Describe the advantages and disadvantages of this technique for diagnosis of stool impaction.

Advantages

• Inexpensive and efficient way to diagnose constipation and fecal impaction.

• Minimal exposure to ionizing radiation

Disadvantages

• Obstructing lesions and masses or focal areas of stenosis and stricturing, causing obstruction and fecal impaction, are not well appreciated on plain radiography.

III. What are the contraindications for the first-line imaging technique?

• There are no significant contraindications to plain radiography. Some institutions may require consent for pregnant patients.

IV. What alternative imaging techniques are available?

• Computed tomography (CT)

V. Describe the advantages and disadvantages of the alternative techniques for diagnosis of stool impaction.

Computed tomography (CT)

Advantages

• May help localize an obstructing lesion or focal area of stenosis or stricture that may lead to a distal colonic obstruction and secondary stool impaction.

Disadvantages

• Exposure to ionizing radiation

VI. What are the contraindications for the alternative imaging techniques?

Computed tomography (CT)

• Contraindicated in pregnant patients, especially within the first two trimesters.