Agar diet caused small bowel blockage in one woman
What it found
A 70-year-old woman who ate a large amount of highly concentrated agar dissolved in boiling water developed hard lumps that blocked her small bowel.
The lumps were removed by surgery.
What they found
Studies in people
Blockage found
Double balloon enteroscopy showed white, hard bezoars clogged in the distal jejunum. About 10 cm of the distal jejunum was blocked.
Surgery and removal
At surgery, many bezoars were found impacted in the distal jejunum. They were removed by enterotomy, and the largest was 5×4×3 cm.
Bezoar composition
Part of a bezoar was analyzed and found to be homogeneously composed of a large amount of dietary fibers. The bezoars were elastic hard, crystallized objects.
Patient history
The patient had type 2 diabetes and sometimes took dietary agar. She had eaten a large amount of highly concentrated agar two days before admission.
Other findings
Agar properties
Agar is produced from red algae and has a high dietary fiber content. It dissolves when heated and forms a gel when cooled, and its fiber is water-soluble.
What the authors conclude
“These bezoars were considered to have formed from highly-concentrated, dissolvable agar.”
Also in their conclusions
- They consider the bezoars to have formed from the highly concentrated, dissolvable agar that the patient had eaten.
- They state that small bowel obstruction occurred due to the formation of bezoars, which had resulted from intake of a large amount of highly concentrated, dissolvable agar.
- They suggest that in the future, if new devices and methods that can smash or remove primary small bowel bezoars safely are developed, endoscopic therapy using DBE might be more easily performed.
How it was done
The authors report this as the first case of small bowel obstruction caused by bezoars formed from highly concentrated, dissolvable agar.
They describe a 70-year-old Japanese woman who came to the emergency room with abdominal pain, nausea and vomiting two days after eating a large amount of highly concentrated agar dissolved in boiling water. They used double balloon enteroscopy and then surgery to find and remove the blockages.
What it can’t tell you
- This is a single case report, so it cannot show that eating agar will cause a blockage in other people.
- It cannot show how often this problem happens or what amount of agar might be risky.
Who paid
- Authors work at
- Juntendo University School of Medicine, Japan
The paper
- Title
- Obstructing small bowel bezoars due to an agar diet: diagnosis using double balloon enteroscopy
- Type
- Case report
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Osada T, Shibuya T, Kodani T, et al (2008). Obstructing small bowel bezoars due to an agar diet: diagnosis using double balloon enteroscopy. Internal medicine (Tokyo, Japan). doi:10.2169/internalmedicine.47.0520Free full textPubMed 18379147DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error