The infant’s story began with vomiting that his parents could not ignore. There was no diarrhea, and nothing in the early course suggested simple enteritis. What alarmed clinicians at the first hospital was the character of the vomit: it was green and bile-like, a warning that something might be obstructing the bowel downstream of the stomach and duodenum. On arrival, the boy’s vital signs were relatively reassuring. His temperature was 37.4 degrees Celsius, his pulse 124 beats per minute, his blood pressure 79 over 48 millimeters of mercury, and his respiratory rate 41 breaths per minute. His peripheral oxygen saturation was a perfect 100 percent on room air. But the physical examination told a more troubling story. His vitality was slightly decreased, his abdomen was distended, and his bowel sounds were diminished.

Curiously, despite what would turn out to be dying bowel inside his abdomen, the infant showed almost no signs of peritoneal irritation, the rebound tenderness and guarding that usually accompany a surgical emergency of this kind. That absence would later prove to be one of the most instructive features of the case. What the boy did have was massive hematochezia, the passage of bloody stool, which is a clinical finding that strongly suggests bowel necrosis. Laboratory tests revealed early-stage inflammation, with a white blood cell count of 15,900 per microliter and a C-reactive protein level of 3.84 milligrams per deciliter, along with slight anemia at a hemoglobin of 12.4 grams per deciliter. Arterial blood gas analysis showed a pH of 7.48 with a bicarbonate level of 19.3 millimoles per liter, a base excess of minus 2.6, and a lactate of 1.0, a pattern consistent with compensated metabolic acidosis.

Abdominal radiography demonstrated findings consistent with ileus, the failure of the bowel to propel its contents, prompting the team to perform contrast-enhanced computed tomography. That scan revealed a closed-loop configuration, and based on a diagnosis of strangulated ileus, the infant was emergently transferred to the authors’ hospital. Only later, and then retrospectively, did reviewers recognize that the CT images had actually shown a bowel-within-bowel appearance that had not been appreciated preoperatively. More importantly, the images displayed a characteristic double-enhanced layer: an inner layer representing necrotic intestine, and an outer layer corresponding to viable colon with preserved blood flow, with fluid accumulation noted between them. The inner layer appeared discontinuous, and frond-like loops of small bowel were visible, resembling a multipolypoid mass.

Ultrasonography, the first-line diagnostic modality in children with suspected intussusception, had failed to show the classic target or doughnut signs. Instead, color Doppler imaging identified only an absence of blood flow within the intestinal wall, a finding that in retrospect resulted from hemorrhagic and necrotic tissue. The authors explain the missing target sign through three pathological mechanisms: necrosis and thickening of the incarcerated bowel, necrosis and dissolution of the mesenteric fat and vessels, and distortion of the bowel configuration caused by the necrotic mesentery. When the normal layered anatomy of the intussusceptum is destroyed in this way, the concentric rings that radiologists rely on simply cease to exist, and the examination that is usually near-definitive becomes misleadingly normal or nonspecific.

The differential diagnosis at the time included internal hernia and strangulated ileus caused by a Meckel’s band. The team also considered a vaccine-related cause. In Japan, the rotavirus vaccine is administered within 14 weeks of birth, and this patient had received it; however, more than a month had passed since vaccination, making a side effect unlikely. With no definitive diagnosis established, the decision was made to proceed with emergency surgery. A nasogastric tube was not inserted before transfer because the child went straight to the operating room, and by the time the tube was placed he had already vomited a small amount of contents. What followed was an operation that tested the surgeons’ ability to read anatomy that had been turned inside out.

Upon opening the abdomen, the surgical team could not immediately identify necrotic bowel, precisely because the dead segment was hidden inside living tissue. Only careful palpation revealed a firm mass within the colon, at which point an intraluminal colonic lesion was suspected for the first time and a colotomy was performed. Necrotic bowel was indeed found within the colonic lumen, confirming the diagnosis of intussusception. Manual reduction using Hutchinson’s maneuver was unsuccessful, so the surgeons resected a 30-centimeter section of small intestine including the necrotic portion. The colon was spared, and the ileocecal valve was preserved. A double-barrel ileostomy was created, with the anal-side small bowel brought out as a mucous fistula. Two months later the stoma was closed, and at one-year follow-up the boy was tolerating oral feeding, growing appropriately, and free of recurrence, with abdominal radiography showing no evidence of obstruction.

Examination of the resected specimen settled the anatomical question: the ileum had invaginated into the colon, confirming an ileoileocolic-type intussusception, with the mesenteric vessels and fat within the invaginated segment completely necrotic and liquefied. This subtype is the crux of the case. The most common form of intussusception in children is the ileocolic type, which can usually be diagnosed easily on ultrasound. The ileoileocolic type is rare, harder to diagnose, and associated with a significantly higher incidence of bowel necrosis. Its success rate for nonoperative reduction is only about 10 percent, which is why the authors argue that it should be diagnosed promptly and treated with surgical intervention rather than reduction by high-pressure enema. In this subtype, the necrotic segment sits within normal bowel, which is exactly why identifying the dead tissue was so time-consuming in the operating room; anticipating it preoperatively, the authors note, would have shortened the operation and reduced the burden on the patient.

The case also resolves a physiological puzzle: why a child with necrotic bowel lacked peritoneal signs. The authors suggest that in intussusception, exudate from the necrotic segment is released into the colonic lumen rather than into the peritoneal cavity, blunting the inflammatory irritation of the abdominal lining that usually signals disaster. Meanwhile, more than 90 percent of childhood intussusception cases are idiopathic, with roughly 5 percent attributable to a pathological lead point such as lymphoid hyperplasia, Meckel’s diverticulum, duplication cysts, intestinal polyps, mesenteric lymphadenopathy, lymphoma, prior surgery, or trauma. In this infant, no cause could be determined, and the small number of reported ileoileocolic cases precludes identifying any region-specific pattern.

Perhaps the most consequential imaging lesson concerns the double-enhanced layer itself. On contrast-enhanced CT, the bowel wall presumed to be necrotic exhibited hyperattenuation and looked deceptively similar to viable bowel, an appearance the authors attribute to capillary hemorrhage originating from the necrotic bowel wall. The team initially interpreted the inner wall as living tissue; it was in fact necrotic mucosa stained by hemorrhage. Misreading this hyperattenuating inner layer as viable intestine could lead clinicians to underestimate the extent of bowel death and delay surgery, with potentially catastrophic consequences. Prior reports had described a multipolypoid appearance on contrast enema and frond-like loops on ultrasonography in this condition, but the authors believe this is the first description of a double-enhanced layer on contrast-enhanced CT in ileoileocolic intussusception mimicking viable bowel. For emergency physicians, radiologists, and pediatric surgeons, the message is stark: when the target sign is missing but a child is sick, the absence of a classic finding may itself be the finding, and the brightest layer on the scan may be the deadest bowel in the abdomen.

Subject of Research: Ileoileocolic intussusception with atypical imaging findings in a pediatric patient

Article Title: Ileoileocolic Type Intussusception With Double Enhanced Layer Sign in a Pediatric Patient: A Case Report

Article References: Sakamoto, N., Take, Y., Nemoto, Y., Ono, K., Tanaka, Y., & Masumoto, K. (2026). Ileoileocolic Type Intussusception With Double Enhanced Layer Sign in a Pediatric Patient: A Case Report. Clinical Case Reports, 14(10), Article e73707. https://doi.org/10.1002/ccr3.73707

Image Credits: AI Generated

DOI: 10.1002/ccr3.73707

Keywords: intussusception, pediatrics, ileoileocolic, contrast-enhanced CT, target sign, bowel necrosis, ultrasonography, emergency surgery, strangulated ileus, case report, double enhanced layer sign, ileostomy

Researchers at the Children’s Hospital of Chongqing Medical University reviewed the records of pediatric patients with intussusception who underwent colonoscopy between 2015 and 2023. Over that nine-year window, 63 children, 34 boys and 29 girls with an average age of 5.46 years, were examined with the flexible endoscope after their intussusception episode. The children had been symptomatic for a median of two days, and most had already undergone a median of two air enemas before the decision was made to look inside the bowel directly. That detail matters, because it frames colonoscopy not as a first-line diagnostic tool but as a second-look procedure reserved for cases in which conventional reduction either fails or raises suspicion of an underlying lesion.

What the endoscopes found was striking. In 31 of the 63 children, nearly half, colonoscopy revealed an abnormality plausibly responsible for the intussusception. The single most common finding was the juvenile polyp, a benign but bulky hamartomatous growth of the colonic mucosa, identified in 23 children. Five children were diagnosed with Peutz-Jeghers syndrome, a rare genetic condition characterized by multiple hamartomatous polyps throughout the gastrointestinal tract and distinctive dark pigmentation of the lips and mouth. Two children turned out to have Burkitt’s lymphoma, an aggressive malignancy of the bowel that can present in the intestine as a mass capable of dragging the bowel wall into itself. A single child had an inflammatory mass. In other words, for roughly one child in two referred to colonoscopy, the intussusception was not an idiopathic event of early childhood but the visible symptom of a defined pathological lesion.

The therapeutic implications were equally significant. Among the 31 children with detected abnormalities, 24 underwent polypectomy through the colonoscope itself, and the team removed a total of 56 polyps. This means that for most of these patients, the diagnostic procedure and the definitive treatment were one and the same: the endoscopist identified the lead point, snared it, resected it, and in many cases retrieved it for histological examination, all without a surgical incision. Only a minority, including the children with Burkitt’s lymphoma, required onward management by other specialties, since a malignant infiltration of the bowel wall is not amenable to endoscopic resection. The study’s authors conclude that colonoscopy can play a genuine dual role, diagnostic and therapeutic, in secondary intussusception, and their numbers give that conclusion real quantitative weight.

To understand why this matters, it helps to consider the mechanics of the disease. Primary or idiopathic intussusception, which predominates in infants between roughly three months and three years of age, is thought to arise from enlarged lymphoid tissue in the terminal ileum, often after a viral infection, and it typically reduces successfully with enema and does not recur. Secondary intussusception is different. Here a discrete anatomical abnormality, a polyp, a tumor, an inverted Meckel’s diverticulum, or an inflamed patch of bowel, serves as the leading edge that gets propelled forward by peristalsis, pulling the adjoining segment with it. Because the lead point persists, air enema reduction may succeed temporarily but the intussusception recurs, or the enema fails outright because the lesion anchors the telescoped segment in place. Older children are disproportionately represented in this secondary group, which fits the study’s average patient age of nearly five and a half years, well beyond the typical idiopathic window.

Current international guidance has been ambivalent about endoscopy in this setting. Many pediatric surgery and radiology protocols recommend that children with recurrent intussusception, failure of nonoperative reduction, or an age atypical for idiopathic disease undergo further imaging, usually ultrasound or computed tomography, to search for a pathological lead point. Ultrasound is fast, noninvasive, and excellent at confirming the intussusception itself, but it is operator dependent and can miss small intraluminal polyps. Computed tomography offers better anatomical resolution but exposes children to ionizing radiation and still may not characterize the mucosal surface. Colonoscopy, by contrast, inspects the mucosa directly at high magnification and in real time, and, crucially, allows immediate intervention. The Chongqing data suggest that when the clinical picture points toward a secondary cause, colonoscopy deserves a more prominent and earlier position in the diagnostic pathway than it has traditionally occupied.

The safety profile of the approach is another important part of the story. Endoscopic polypectomy in children is an established technique, but performing it in a bowel segment that has recently been intussuscepted raises theoretical concerns about perforation, edema, and compromised tissue viability. The fact that 24 children in this series underwent endoscopic polypectomy without the series reporting widespread complications lends practical reassurance, although the retrospective design means the report is best read as an experience-based series rather than a controlled comparison. The authors obtained informed consent from parents or guardians for all participants, and the study was conducted under institutional ethics approval in line with the Declaration of Helsinki, reflecting the sensitivity of endoscopic intervention in a pediatric emergency context.

There are also broader lessons for practicing clinicians. A child who presents with intussusception after the age of three, who has had more than one episode, or who fails initial air enema reduction should prompt a search for a lead point rather than repeated enemas alone. The finding that five of 63 children in this cohort had Peutz-Jeghers syndrome is particularly noteworthy, because that diagnosis carries lifelong implications well beyond the acute episode: patients require regular surveillance endoscopy for polyp burden and carry elevated cancer risk that mandates structured follow-up into adulthood. Similarly, the two cases of Burkitt’s lymphoma underscore that intussusception can be the first manifestation of a life-threatening malignancy, and that the histological examination of any resected lead point is not a formality but a critical diagnostic step that may redirect the entire course of care.

Limitations of the study are worth keeping in view. As a single-center retrospective analysis, it cannot establish how frequently secondary intussusception occurs across the wider population, nor can it define the optimal timing of colonoscopy relative to enema attempts. The 63 children represent a selected group in whom endoscopy was already deemed appropriate, so the near-50 percent yield of abnormalities should not be extrapolated to all children with intussusception, most of whom will never need a scope. Selection bias likely inflates the detection rate relative to an unselected cohort, and the authors did not report long-term recurrence outcomes after polypectomy, which would be the ultimate test of whether removing the lead point prevents future episodes.

Even with those caveats, the study adds meaningful evidence to a long-standing clinical debate. It demonstrates, in a substantial pediatric cohort and across nearly a decade of practice, that colonoscopy is both feasible and frequently decisive in children whose intussusception is suspected to be secondary. For the 24 children spared an open operation, and for the families who left the hospital with a specific diagnosis rather than a mystery, the flexible scope did what it does best in modern medicine: it looked directly at the disease and, in the same sitting, removed it. As pediatric centers refine their protocols for recurrent and atypical intussusception, this work makes a strong case that the colonoscope should no longer be an afterthought but a planned, early step in the evaluation of the child whose bowel keeps telescoping for reasons the enema cannot explain.

Subject of Research: The use of colonoscopy to diagnose and treat secondary intussusception in children

Article Title: Colonoscopy in the diagnosis and treatment of secondary intussusception

Article References: Hou, J., Cao, F., Cui, M., Wang, Y., Liu, W., Feng, W., & Guo, Z. (2026). Colonoscopy in the diagnosis and treatment of secondary intussusception. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07636-2

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07636-2

Keywords: intussusception, colonoscopy, pediatrics, juvenile polyps, Peutz-Jeghers syndrome, Burkitt's lymphoma, endoscopy, air enema, polypectomy, children's hospital, intestinal obstruction, diagnosis

Methimazole is a first-line antithyroid medication that works by blocking the enzyme thyroid peroxidase, thereby curtailing the synthesis of thyroid hormone in patients with autoimmune thyrotoxicosis, most commonly Graves’ disease. The drug is generally well tolerated, but its most feared adverse effect is agranulocytosis, an idiosyncratic hematologic reaction in which the absolute neutrophil count plummets, typically to below 0.5 × 10⁹ per liter. The incidence is low—classically estimated at 0.2 to 0.5 percent of treated patients—but the consequences can be devastating, because neutrophils are the principal cellular effectors of innate immunity against bacteria and fungi. Without them, mucosal barriers in the mouth, throat, and gut become portals for overwhelming infection.

In this case, the patient had been taking methimazole for approximately one month when she presented with fever, pharyngitis, abdominal pain, and diarrhea. The timing is clinically significant: methimazole-induced agranulocytosis most often emerges within the first two to three months of therapy, which is precisely the window in which guidelines recommend vigilance for symptoms such as sore throat and fever. Laboratory evaluation confirmed the severity of her condition, revealing an absolute neutrophil count of just 0.01 × 10⁹ per liter—essentially a complete absence of circulating neutrophils—alongside markedly elevated inflammatory markers indicating a systemic inflammatory response already in progress.

What distinguished this case from the typical presentation of drug-induced agranulocytosis was what imaging revealed next. Computed tomography confirmed an ileocolic intussusception, with the terminal portion of the small intestine having invaginated into the colon. Intussusception is common in infants, where it is usually idiopathic, but in adults it is rare and almost always associated with a pathological lead point such as a polyp, tumor, or—critically in this patient’s situation—disordered motility and inflammatory change driven by severe sepsis. Even more alarming, surgical findings showed transmural necrosis of the involved bowel segment, meaning the intestinal wall had died through its full thickness, a condition that rapidly becomes fatal without resection.

The clinical team faced a genuine dilemma. Emergency surgery in a patient with profound neutropenia and septic shock carries extraordinary risks: the patient has minimal capacity to heal, to fight surgical-site infection, or to withstand the physiological insult of laparotomy. Profound neutropenia has traditionally been regarded as a relative contraindication to major emergency surgery. Yet the authors argue that when septic shock results from intestinal necrosis, the necrotic bowel itself is the source of the sepsis, and no amount of antibiotics will achieve cure without source control. The patient underwent an emergency ileocolic resection with a temporary ileostomy, removing the dead segment and diverting the fecal stream to protect the anastomosis.

Perioperative and postoperative management was aggressively multidisciplinary. The team administered broad-spectrum intravenous antibiotics to cover the gut flora flooding into tissues and bloodstream, and administered granulocyte colony-stimulating factor, or G-CSF, a recombinant growth factor that stimulates the bone marrow to produce and release neutrophils. G-CSF has become standard supportive care in antithyroid drug-induced agranulocytosis, shortening the duration of neutropenia, although its effect on mortality in septic neutropenic patients remains debated. The patient also required multi-organ support in the intensive care unit, reflecting the degree to which septic shock had compromised her cardiovascular and other organ systems.

The authors place their case in the context of a literature review of comparable reports, noting that gastrointestinal complications of agranulocytosis—ranging from necrotizing enterocolitis-like presentations to sepsis-driven bowel perforation—are exceedingly uncommon but well documented. The mechanism they propose for the intussusception is instructive: sepsis and severe inflammation can disrupt normal intestinal peristalsis, creating uncoordinated, spastic bowel contractions. In an adult bowel already weakened by inflammatory injury and mucosal breakdown, these dyskinetic segments can serve as the lead point for telescoping. This reframes intussusception not merely as a mechanical accident but as a potential downstream consequence of systemic immunoparalysis and septic physiology.

The broader lessons of the case concern monitoring and clinical decision-making. The authors emphasize the critical need for vigilant hematologic surveillance in patients starting methimazole, particularly during the first months of therapy. Current practice varies internationally: routine serial white cell counts are not universally recommended because agranulocytosis is unpredictable and idiosyncratic, unrelated to dose in most cases, but all guidelines agree that any patient on antithyroid medication who develops fever or sore throat must have an urgent differential blood count. The message for patients is equally important—symptoms that might suggest an ordinary upper respiratory infection can, in this context, signal a hematologic emergency.

Equally consequential is the paper’s stance on surgery in neutropenic sepsis. By demonstrating a successful outcome after emergency bowel resection in a patient whose neutrophil count was essentially zero, the authors argue that profound neutropenia should not be treated as an absolute contraindication to life-saving source control. The decision framework they describe is one of weighing the mortality of untreated necrotic bowel—approaching certainty—against the substantial but potentially survivable risks of surgery supported by antibiotics, G-CSF, and intensive care. Their conclusion that a multidisciplinary approach involving emergency physicians, endocrinologists, hematologists, surgeons, and intensivists is essential for successful outcomes reflects a growing consensus in the management of complex drug toxicities.

The case also carries a public health dimension. Hyperthyroidism affects a substantial fraction of the population, particularly women, and antithyroid drugs remain the standard initial therapy worldwide, especially in regions where radioactive iodine and surgery are deferred or unavailable. Agranulocytosis, while rare, is a reminder that even familiar, decades-old medications demand respect for their idiosyncratic risks. The Fujian team’s detailed documentation—supported by funding from the Joint Funds for the Innovation of Science and Technology of Fujian Province and approved by their institutional ethics committee with the patient’s written informed consent—adds a valuable data point to a sparse literature, and offers clinicians a template for recognizing and responding to one of the most dangerous intersections of endocrinology, hematology, and emergency surgery.

Subject of Research: Methimazole-induced agranulocytosis complicated by sepsis and ileocolic intussusception

Article Title: Methimazole-induced agranulocytosis complicated by sepsis and ileocolic intussusception: a case report and literature review

Article References: Zhu, X., Zhang, H., Lin, J., Pang, M., Zhang, X., Dong, Y., Huang, Y., & Li, Y. (2026). Methimazole-induced agranulocytosis complicated by sepsis and ileocolic intussusception: a case report and literature review. BMC Endocrine Disorders. https://doi.org/10.1186/s12902-026-02569-4

Image Credits: AI Generated

DOI: 10.1186/s12902-026-02569-4

Keywords: methimazole, agranulocytosis, sepsis, intussusception, hyperthyroidism, adverse drug reaction, G-CSF, neutropenia, thyrotoxicosis, emergency surgery, BMC Endocrine Disorders, case report