A previously healthy infant presents with a recurrent episode of abdominal pain. The mother says that the child has been passing an altered stool after episodes of pain, but gives no history of vomiting or bleeding per diagnosis -rectum. Which of the following is the most likely diagnosis –
**Core Concept**
The infant's presentation of recurrent abdominal pain, altered stool, and absence of vomiting or rectal bleeding suggests a diagnosis related to the enteric nervous system's dysfunction. This condition is characterized by a failure of the normal peristaltic movement of the intestine, leading to a functional obstruction.
**Why the Correct Answer is Right**
The infant's symptoms are consistent with a diagnosis of **Hirschsprung's disease**, a congenital condition where the enteric nervous system is absent from the distal bowel, leading to an inability to relax the anal sphincter and pass stool. This results in a functional obstruction, causing the child to pass altered stool and experience abdominal pain. The absence of vomiting or rectal bleeding is characteristic of this condition. The clinical presentation is often described as a "failure to pass meconium" in the first 48 hours of life, but in this case, the presentation is delayed.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately describe the clinical presentation of Hirschsprung's disease. While constipation is a feature, the key symptom is the passage of altered stool.
**Option B:** This option is incorrect as it describes a condition that is not directly related to the enteric nervous system's dysfunction. The symptoms of intestinal obstruction, such as vomiting and abdominal pain, are not present in this case.
**Option C:** This option is incorrect as it describes a condition that is not consistent with the clinical presentation of Hirschsprung's disease. The passage of altered stool is a key feature, but the absence of rectal bleeding makes this diagnosis less likely.
**Clinical Pearl / High-Yield Fact**
A key feature of Hirschsprung's disease is the presence of a "transition zone" between the affected and normal bowel, where the enteric nervous system is present. This zone can be identified during a barium enema or surgical exploration.
**Correct Answer:** C. Hirschsprung's disease