Differential Diagnosis for a 15-month-old Boy with Worsening Constipation
- Single most likely diagnosis:
- Constipation with anal fissure: The patient's symptoms of chronic constipation, straining during bowel movements, and thin-caliber stools are consistent with constipation. The presence of bright-red blood and positive stool occult blood testing suggests an anal fissure, which is a common complication of constipation in children.
- Other Likely diagnoses:
- Cow's milk protein allergy or intolerance: The worsening of symptoms after transitioning from breast milk to cow's milk at age 1 suggests a possible allergy or intolerance to cow's milk protein.
- Functional constipation: The patient's chronic constipation and lack of response to dietary changes suggest functional constipation, which is a common condition in children.
- Gastroesophageal reflux disease (GERD): Although not directly related to constipation, GERD can cause abdominal discomfort and tenderness, which may contribute to the patient's symptoms.
- Do Not Miss diagnoses:
- Intussusception: Although less likely, intussusception is a life-threatening condition that can cause abdominal pain, vomiting, and bloody stools. It is essential to consider this diagnosis, especially given the patient's abdominal tenderness and positive stool occult blood testing.
- Hirschsprung's disease: This congenital condition can cause severe constipation and intestinal obstruction. Although the patient's age and lack of other symptoms make this diagnosis less likely, it is crucial to consider it due to its potential severity.
- Rare diagnoses:
- Cystic fibrosis: This genetic disorder can cause gastrointestinal symptoms, including constipation and malabsorption. However, the patient's lack of other symptoms, such as respiratory issues or failure to thrive, makes this diagnosis less likely.
- Neurological disorders (e.g., spinal cord abnormalities): Certain neurological conditions can cause constipation and abdominal symptoms. However, the patient's normal development and lack of other neurological symptoms make this diagnosis unlikely.