A Case of Pneumatosis Intestinalis With Pneumoperitoneum as a Potential Delayed Adverse Effect of Capecitabine

Ileitis and colitis are known complications of capecitabine when used in patients with gastrointestinal cancers. However, to our knowledge, pneumatosis intestinalis (PI) has not previously been reported with this medication. We present a patient with breast cancer, without any metastases to the gastrointestinal tract, who presented with persistent diarrhea 4 weeks after discontinuing adjuvant capecitabine, which was found to be due to PI. As she had no other risk factors or identifiable causes, her PI was attributed to a delayed reaction to capecitabine. This case highlights the need to consider PI earlier in the differential diagnosis in patients with breast cancer who present with unexplained diarrhea after recent discontinuation of capecitabine.