Differential Diagnosis for a 3-month-old with Excessive Gas
- Single most likely diagnosis
- Functional gastrointestinal disorder (e.g., infantile gas, colic): This is the most common cause of excessive gas in infants, often due to swallowing air during feeding or an immature digestive system.
- Other Likely diagnoses
- Lactose intolerance: Some infants may have difficulty digesting lactose, leading to gas and discomfort.
- Formula intolerance: Similar to lactose intolerance, some infants may react to certain formulas, causing gas and other symptoms.
- Overfeeding or improper feeding technique: Feeding too much or too quickly can lead to swallowing air and excessive gas.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Intestinal obstruction: Although rare, conditions like pyloric stenosis, intussusception, or volvulus can cause severe vomiting, abdominal distension, and gas.
- Hirschsprung's disease: A congenital condition characterized by the absence of nerve cells in the colon, leading to severe constipation, gas, and potentially life-threatening complications.
- Gastroesophageal reflux disease (GERD): While not typically fatal, untreated GERD can lead to significant morbidity, including feeding difficulties, failure to thrive, and respiratory complications.
- Rare diagnoses
- Congenital sucrose-isomaltase deficiency: A rare genetic disorder affecting carbohydrate digestion, leading to gas, bloating, and diarrhea.
- Fructose malabsorption: Some infants may have difficulty absorbing fructose, resulting in gas, bloating, and other gastrointestinal symptoms.
- Small intestine bacterial overgrowth (SIBO): Although more common in older children and adults, SIBO can occur in infants, particularly those with underlying medical conditions or anatomical abnormalities.