Functional Diarrhea in Toddlers (Chronic Nonspecific Diarrhea)

Abstract

Chronic nonspecific diarrhea (CNSD) is a leading cause of chronic diarrhea in otherwise well children, 1–3 years of age, and occurs, by definition, without underlying nutrient malabsorption. CNSD has been classified by the consensus committee Rome III within the functional digestive disorders of infancy and childhood, and its salient features and diagnostic criteria have been recently defined. Patients with CNSD typically look healthy, well nourished, and active and have a pattern of intermittent or nearly constant runny stools containing recognizable undigested vegetable. Often CNSD begins following a viral gastroenteritis. In most cases, the mechanism of diarrhea appears to be related to habitual excessive intake of hyperosmolar fluids such as soft drinks and fruit juices, as well as products that contain fructose or sorbitol. A pathogenic relationship exists, too, between CNSD and the ingestion of a diet low in fat. When the anomalous dietary patterns are corrected and the child’s diet is normalized, the typical result is a sustained return to normal stools.

The evaluation of children with chronic diarrhea requires a complete clinical history and a sound physical examination. Dietary factors are the mainstay of the history and of the subsequent diagnostic rationale. When laboratory tests are performed, these should reveal no abnormalities and be consistent with a normal nutritional and absorptive status. In daily practice, the typical symptom complex of CNSD is often mistakenly labeled as secondary to lactose intolerance, intestinal “immaturity,” food allergy, small bowel bacterial overgrowth syndrome, or other entities. These tentative diagnoses are then characteristically followed by the prescription of unsubstantiated treatments, including restrictive dietary regimes. Indeed, in the absence of warning signs, the sound management of CNSD should be based on the immediate prescription of a normal dietary regime, with a drastic reduction in the excessive fluid intake and the suppression of hyperosmolar and carbonated drinks and industrial juices.