Small Bowel Obstruction Due to Mochi (Rice Cake): A Case Report and Review of the Literature

Abstract

A 66-year-old man presented at our emergency department with severe intermittent abdominal pain. His history revealed that he had eaten several mochi (rice cakes) without sufficiently chewing them before swallowing. Following computed tomography that showed a high value, he was diagnosed with an obstruction caused by mochi. Although mochi obstruction can sometimes improve with conservative treatment, this case required laparotomy. Medical literature in English on small bowel obstruction due to mochi is rare, but fortunately in this case we were able to collect complete laboratory and imaging data. Furthermore, due to the surgical findings, we could clearly diagnose the pathophysiology of mochi obstruction. Here we describe a case of small bowel obstruction due to mochi, and review the literature to determine the characteristics of intestinal obstruction caused by it.

New Year's silent killer in Japan: Undigested mochi

“…Ten‐millimeter mochi can be drained to the duodenum from the pylorus ring, where it can then be dissolved by bile and pancreatic juice. 2 …”

“…Ten-millimeter mochi can be drained to the duodenum from the pylorus ring, where it can then be dissolved by bile and pancreatic juice. 2 Although airway obstruction by mochi is well recognized, a gastro-intestinal foreign body associated with mochi is poorly recognized because of its rarity. Retained mochi can cause severe gastric ulcer which possibly leads to gastric perforation.…”

“…Two days after snare cutting, endoscopy revealed that all the mochi had disappeared, and abdominal CT revealed no residual mochi in the intestine. Ten‐millimeter mochi can be drained to the duodenum from the pylorus ring, where it can then be dissolved by bile and pancreatic juice 2 …”

Unhappy new year: mochi-induced small bowel obstruction

“…This property is due to the fact that amylopectin, the main ingredient of mochi, does not dissolve in hot water, and the process of kneading makes it indigestible. 2 Second, factors that interfere with chewing, including dentures, difficulty swallowing and missing teeth, can also lead to mochi-induced bowel obstruction. 2 3 Seasonality of the disease is a key feature.…”

Elderly woman with abdominal pain

“…Rice cakes, known as mochi, traditionally eaten during the Japanese New Year, may be consumed all year‐round. The main component of this meal is indigestible amylopectin 1 . Several case studies report that rice cakes may cause small bowel obstruction if inadequately chewed, with >20 mm bezoars forming, and in some cases, surgery may be required 2 .…”