# The Use of Sucroferric Oxyhydroxide Prior to Sigmoidoscopy in Patients With End-Stage Kidney Disease: A Case Report

## TL;DR

A patient with kidney disease had poor bowel prep for a colonoscopy due to a phosphate binder, leading to repeated procedures and delays.

## Contribution

This case report highlights the previously unaddressed issue of sucroferric oxyhydroxide interfering with bowel preparation for endoscopy.

## Key findings

- Sucroferric oxyhydroxide can cause 'charcoal-like' material in the bowel, impairing endoscopic visualization.
- Discontinuing the medication for two weeks improved bowel preparation and allowed successful visualization.
- The case underscores the clinical and economic consequences of inadequate bowel prep in transplant candidates.

## Abstract

Sucroferric oxyhydroxide is an iron-based phosphate-binding medication that has been approved for the treatment of hyperphosphatemia in patients with end-stage kidney disease. Given the low overall iron release from the polynuclear iron(III)-oxyhydroxide molecule, recommendations regarding its use prior to colonoscopy/sigmoidoscopy have not been developed.

A 51-year-old male with a known history of end-stage renal disease treated with hemodialysis was referred to Gastroenterology for consideration of colonoscopy to rule out malignancy because of a history of rectal bleeding. This was to be completed prior to proceeding with a living-donor kidney transplant.

Flexible sigmoidoscopy done after non-diagnostic colonoscopy demonstrated diffuse “charcoal-like” material that prevented adequate visualization of the bowel despite standard bowel preparation. The findings were believed to be secondary to the use of sucroferric oxyhydroxide prescribed for hyperphosphatemia.

The patient was subsequently instructed to discontinue sucroferric oxyhydroxide for 2 weeks prior to his repeat sigmoidoscopy procedure.

The patient’s repeat sigmoidoscopy after discontinuing sucroferric oxyhydroxide allowed for adequate bowel visualization that revealed only a benign lipoma.

This case demonstrates the potential for sucroferric oxyhydroxide use to result in poor bowel preparation and resulting inadequate visualization on lower gastrointestinal endoscopy. It serves to highlight the clinical implications leading to the need for repeated procedures, which contributes to resource waste and unnecessary costs to the healthcare system, as well as delays in diagnostic evaluation required for transplantation; patient frustration was evident.