In a sobering reminder that we are all just sentient bags made up of lots of smaller bags, a video recently shared to Twitter demonstrates the medical emergency that gives rise to the "doughnut sign”. Intestinal intussusception is the culprit, a condition in which the intestine effectively folds in on itself that can lead to an obstruction and even a loss of blood flow to the bowel.
The doughnut sign is a fun nickname given to the radiological presentation of intestinal intussusception, though it’s also known as the target sign. You can get doughnut signs elsewhere in the body that correspond to different conditions, but in the case of gastroenterology, it applies to a complication of the intestine whereby a segment of the bowel telescopes into an adjacent bowel segment.
If you’re struggling to visualize exactly what a human intestine telescoping in on itself looks like, Dr Keith Siau – a gastrointestinal doctor who you may remember from Ladybug Stars In A Colonoscopy – shared an eye-opening video on Twitter to demonstrate. It seems Great Ormond Street Hospital For Children in the UK really hit the nail on the head when they said: “It is a bit like a getting a sock turned inside itself.”
“This process can lead to multiple complications such as bowel obstruction, bowel necrosis, and sepsis,” wrote Dr Andrew Brill and Dr Richard Lopez in a 2022 article about intestinal intussusception. “The disease process is much more common in the pediatric population and uncommon in adults, but when present is likely due to a pathological lead point such as [a growth].”
For infants, intestinal intussusception is the most common abdominal emergency with symptoms including “currant jelly stool” (caused by blood and mucus in feces), a mass in the belly, severe pain that may come and go, and vomiting. However, these symptoms are non-specific and not all patients present with them, making reaching a diagnosis tricky for some patients.
The doughnut sign is a radiological indicator that something’s gone awry with the bowel, which on ultrasound looks like a ring inside another ring, sort of like a doughnut. If a diagnosis is made, an air enema can be enough to fix the problem by inflating the bowel and straightening it out again.
Complicated cases may require surgery to set right, which can be done as a keyhole surgery (laparoscopically). Other times a bigger surgery may be needed to open up the abdomen so that surgeons can gently squeeze the bowel and reverse the intussusception and make sure that normal blood flow returns to the organ.
Isn’t the human body a trip?