Opioids are a mainstay of treatment for moderate to severe
cancer pain. At present,
oxycodone has fewer adverse effects compared to
morphine and is widely used for
cancer pain therapy. The adverse effects of
oxycodone are similar to
morphine and include
constipation,
nausea, and sedation. However, acute
abdominal pain is rarely seen. Here, we describe a
cancer patient presenting with
acute abdomen with stercoral
diarrhea. A 54-year-old man with
squamous cell carcinoma of the external auditory canal had been taking
oxycodone for
pain relief. The patient had taken
oxycodone for several months and had never complained of either
diarrhea or
constipation. After an increase in the dosage of
oxycodone, he complained of abdominal distension and
constipation. After being administered a
laxative, he complained of
diarrhea and severe
abdominal pain. He visited the emergency department and was diagnosed with acute colonic obstruction caused by severe
constipation. He self-medicated with
oxycodone at dosages of up to 180 mg/day, and this abrupt increase of
oxycodone caused stercoral
diarrhea. Finally, total blockage of stool developed, resulting in
acute abdomen.