American Board of Family Medicine (ABFM) Practice Exam 2026 - Free ABFM Practice Questions and Study Guide

The first-line treatment for fecal impaction in infants is an oral osmotic agent such as polyethylene glycol 3350. This approach is favored because osmotic agents draw water into the intestines, softening the stool and promoting its passage. This mechanism is effective and generally safe for infants, making it an ideal initial treatment option.

While other treatments can be beneficial in managing constipation or fecal impaction, they may not be as appropriate as the oral osmotic agent in this specific scenario. For instance, while enemas can provide immediate relief, they may not be suitable for regular use in infants due to the risk of dehydration or electrolyte imbalances. Increasing dietary fiber is more of a preventive measure rather than an immediate treatment for an already existing impaction. Similarly, while certain laxatives can have their place in treatment, they might not be the first-line choice due to their potential side effects and the specific needs of the infant's gastrointestinal system.

Overall, the use of an oral osmotic agent effectively addresses fecal impaction while being gentle enough for an infant's developing system.