Surgery for suspected appendicitis is one of the most familiar operations in emergency medicine. But case reports from Qatar, Nepal, Greece, Portugal, and now Ecuador describe a recurring surprise: the real culprit was a swallowed fish bone that had punctured a Meckel's diverticulum, a small pouch on the small intestine left over from fetal development.
The latest case, published Sept. 18 in the Journal of Surgical Case Reports, involved a 73-year-old woman in Quito who blamed her belly pain on food poisoning after a seafood meal and treated herself with over-the-counter pain relievers for four days. The Ecuadorian surgeons counted fewer than 50 English-language reports of fish bones perforating these pouches, so the injury is rare. When it does happen, it is notoriously hard to identify before surgery.
A Pouch Hiding in Appendix Territory
Meckel's diverticulum forms when a duct connecting the fetal gut to the yolk sac fails to close. It is found in about 2% of people, and most never know they have one. Symptoms develop in only about 4% to 16%, according to a 2025 report in the International Journal of Surgery Case Reports, usually as bleeding, blockage, or inflammation.
The pouch sits on the last stretch of the small intestine, often not far from the appendix. When something sharp pierces it, the result can be the same right-sided abdominal pain, tenderness, fever, and elevated white blood cell count that point doctors toward appendicitis.
Case After Case Looked Like the Appendix
In a 2022 report from Hamad Medical Corporation in Doha, a 24-year-old man arrived with signs and symptoms suggestive of acute appendicitis. A CT scan instead showed a foreign body perforating a protrusion outside the small bowel, and laparoscopy found a fish bone piercing his Meckel's diverticulum.
In Eastern Nepal, a 45-year-old man came in with a day of right lower abdominal pain, fever, nausea, and loss of appetite. He had rebound tenderness and an elevated white blood cell count; his Alvarado score, a common appendicitis checklist, was 7 out of 10, and an outside ultrasound had suggested an inflamed appendix. During surgery, the appendix did not explain what surgeons saw, so they examined the bowel and found a perforated Meckel's diverticulum with a fish bone, according to their 2024 report.
A 53-year-old Nepali man in the 2025 report went further down the appendicitis path. With a provisional diagnosis of appendicitis, he underwent an open appendectomy, and only during the operation did surgeons find the intact fish bone that had perforated his pouch. In an earlier case from Greece, a 64-year-old man taken to surgery for suspected appendicitis had a nearly normal-looking appendix and an inflamed Meckel's diverticulum pierced by a fish bone.
The woman in Ecuador was luckier in one respect. Her CT scan showed a dense object about 2 centimeters long in her bowel, and laparoscopic surgery found a 5-centimeter pouch with the bone poking through its tip. Surgeons removed the pouch with a stapling device, and she was doing well at follow-up.
Why the Real Culprit Is So Easy to Miss
Portuguese surgeons who described a 53-year-old woman with this injury in a 2019 report wrote that symptoms and imaging features are nonspecific, and that ultrasound and CT often struggle to distinguish the pouch from ordinary loops of bowel. Most cases, they noted, are diagnosed in the operating room.
Patient history does not always help, either. People rarely remember swallowing a bone, and the Ecuador authors noted that fewer than half of patients report one. In that case, the seafood meal was a real clue that pointed toward the wrong explanation.
Fish bones are not the only culprits. The Portuguese team listed wood splinters, bay leaves, melon seeds and chicken bones among foreign bodies reported to perforate these pouches, and cited a review of 52 complicated Meckel's diverticula in which 8% needed surgery because of a swallowed foreign body. In a separate report, a splinter-like object perforated the pouch of a 13-year-old boy who was first suspected of having appendicitis. That report's literature review found fish bones account for about 55% of such foreign body cases.
The Unsettled Question in the Operating Room
The recurring surprise has practical consequences. Several of these reports stress the value of examining the small intestine when the appendix looks too normal to explain a patient's illness, as the Nepal team did.
A related question remains open. When surgeons find a Meckel's diverticulum that is causing no problems, there is no clear consensus on whether to remove it. Arizona surgeons who treated a 54-year-old woman whose perforated pouch was found only after an appendectomy discussed that dilemma and noted that the available research remains inconclusive. Taking out a harmless pouch adds surgical risk, while leaving it carries a small chance of future complications.
For the public, the takeaway is modest. Most swallowed fish bones pass without harm, and most people with a Meckel's diverticulum will never know it. But severe or worsening pain in the lower abdomen, especially with fever, vomiting or tenderness, deserves prompt medical evaluation, whatever a person thinks caused it. Mentioning a recent fish meal can give clinicians a useful clue.
Key Questions Answered
What is a Meckel's diverticulum?
It is a small pouch on the small intestine left over from fetal development. About 2% of people have one, and most never develop symptoms.
Why can a fish bone in this pouch look like appendicitis?
The pouch sits on the lower small intestine, often near the appendix, so a perforation there can cause similar right-sided pain, tenderness, fever, and blood test changes.
Can a CT scan detect it?
Sometimes. Scans have shown the foreign body in some cases, but surgeons report that imaging often cannot tell the pouch apart from normal bowel, and many cases are diagnosed during surgery.
How is it treated?
Surgeons remove the bone and the affected pouch, often laparoscopically with a stapling device or by removing a small wedge or section of bowel.
Should a Meckel's diverticulum found by chance be removed?
There is no clear consensus. Research on removing pouches that cause no symptoms remains inconclusive.
When should abdominal pain prompt a visit to a doctor?
Severe, worsening, or persistent lower abdominal pain, especially with fever or vomiting, should be evaluated promptly by a clinician.
Published by Medicaldaily.com
