Sodium polystyrene sulfonate (SPS) is commonly prescribed for the management of hyperkalemia, a critical electrolyte imbalance contributing to over 800000 annual visits to emergency departments.

To conduct a systematic review of documented cases of SPS-induced colitis and assess its associated prognosis.

Following the PRISMA-P guidelines, our study employed Medical Subject Headings and Health Sciences Descriptors, skillfully combined using Boolean operators, to conduct comprehensive searches across various electronic databases, including Scopus, Web of Science, MEDLINE (PubMed), BIREME (Biblioteca Regional de Medicina), LILACS (Latin American and Caribbean Health Sciences Literature), SciELO (Scientific Electronic Library Online), Embase, and Opengray.eu. Language criteria were confined to English, Spanish, and Portuguese, with no limitations on the publication date. Additionally, we manually scrutinized the reference lists of retrieved studies. To present our findings, we utilized simple descriptive analysis.

Our search strategy yielded a total of 442 references. After rigorous evaluation, we included 51 references, encompassing 59 documented cases of colitis. Predominant clinical presentations included abdominal pain, observed in 35 (60.3%) cases, and bloating, reported in 18 (31%) cases. The most frequently affected sites of inflammation were the cecum, rectum, and small intestine, accounting for 31%, 25.8%, and 22.4% of cases, respectively. Colonoscopy findings were described in 28 (48.2%) cases, and 29 (50%) of patients required surgical intervention. Among the subset of patients for whom outcome data was available, 39 (67.2%) experienced favorable outcomes, while 12 (20.6%) unfortunately succumbed to the condition. The mean time required for resolution was 36.7 d, with a range spanning from 1 to 120 d.

SPS demonstrates the capacity to effectively lower serum potassium levels within 24 h. However, this benefit is not without the risk of bowel injury. Our study highlights the absence of high-quality data pertaining to the incidence of adverse events associated with SPS usage, making it challenging to determine whether the potential risks outweigh the benefits. However, a significant mortality rate related to SPS-induced colitis was noted. Future investigations should prioritize randomized controlled trials with a sufficiently large patient cohort to ascertain the true utility and safety profile of this medication.

• Sodium polystyrene sulfonate
• Hyperkalemia
• Colitis
• Bowel necrosis
• Kayexalate

We present the case of a 23-year-old patient who developed a severe gastric ischemia after the ingestion of a single dose of sodium polystyrene sulfonate (SPS) orally. Emergency surgery confirmed extensive full thickness gastric necrosis, prompting a total gastrectomy. Histopathology showed kayexalate crystals in the gastric wall, suggesting SPS-related ischemic gastritis. After radical resection of the affected stomach, this young patient was able to fully recover. Although effective, the widespread use of SPS to treat hyperpotassemia remains a debated topic because of rare but serious adverse events like the forming of kayexalate crystal residues in the gastrointestinal tract. These crystal residues are mostly found in the large intestine and can lead to ulceration and necrosis. Physicians need to be aware of this rare but potentially devastating adverse effect of SPS ingestion.

• hemodialysis
• hyperkalemia
• kayexalate crystals
• kayexalate®
• rectal ulcer