Rationale: Hirschsprung disease (HD) or colonic aganglionosis is a congenital disorder, which results from the abnormal migration of neuronal cells of the neural crest leading to a disorder of the enteric nervous system consisting in the absence of ganglion cells within the submucosal and myenteric plexus.
Patient concerns: We report the case of a 7-month-old female infant admitted in our clinic for constipation and failure to thrive. At the age of 6 months, she was examined in our clinic for the same reasons, and we recommended symptomatic treatment without improvements. The clinical examination revealed pallor of the skin and mucosa, distended abdomen, and abdominal tenderness at palpation.
Diagnoses: The abdominal ultrasound showed abdominal bloating, and the barium enema was normal. The patient's evolution worsened progressively within the following 3 days after admission associating sings of toxic megacolon.
Interventions: She underwent a surgical intervention with total colectomy and ileostomy, and the final diagnosis confirmed by the histological examination was of total colonic aganglionosis (TCA).
Outcomes: The evolution immediately after the surgery and the follow-up examination after approximately 3 months pointed out normal weight gain and the laboratory tests were within normal limits.
Lessons: TCA can also manifest in older infants. Barium enemas can guide the diagnosis in most cases of HD. Nevertheless, in patients with TCA, it can be normal. Moreover, it could represent a trigger for toxic megacolon.