A Case of Congenital Diarrhea


Dr.Jerin.K.John,Dr.Bhanu Vikraman Pillai,Dr.Anupa Achama Thomas ,Dr.Neeraj Panchanadikar(ped gastro),Dr.C.Jayakumar AIMS KOCHI 

A term female neonate, born to a 22-year-old mother via full-term normal delivery (FTND), weighed 3.5 kg at birth with Apgar scores of 9 at 1 minute and 10 at 5 minutes is noted to have watery loose stools after delivery hence shifted to NICU 
This pregnancy was largely uneventful, but due to a family history of previous infant deaths related to severe dehydration, acute renal failure (ARF), cerebral edema, and hypernatremia, amniocentesis was performed. This revealed a homozygous mutation in the SLC5A1 gene, a rare cause of congenital diarrhoea
Physical examination upon admission was unremarkable, with no visible congenital anomalies, and initial laboratory tests, including a complete blood count (CBC) and sepsis workup, were normal.
Due to the persistence of diarrhoea even with expressed breast milk (EBM), the infant was started on to a soy-based formula, which was initially well-tolerated. 
However, considering the known genetic mutation, a specialized carbohydrate-free formula was prepared and given to the child, which the infant tolerated well. Stool tests showed a positive stool reducing substance, consistent with carbohydrate malabsorption. The homozygous mutation in the SLC5A1 gene indicated a defect leading to severe diarrhea upon the ingestion of certain sugars. The infant was managed with aggressive fluid and electrolyte replacement, administered parenterally and via a nasogastric tube, due to significant ongoing fluid losses. After changing to the specialized carbohydrate-free formula, the infant’s diarrheasubsided, and the need for extensive fluid replacement reduced 
. This case underscores the importance of early genetic testing and appropriate dietary management in neonates with a family history suggestive of congenital diarrhea.

Differential Diagnosis (DD)
Congenital Causes of Diarrhea:
Glucose-galactose malabsorption (confirmed)
Congenital chloride diarrhea
Congenital sodium diarrhea
Other Considerations:
Infectious causes of neonatal diarrhea (ruled out negative sepsis workup)

Disscusion
Congenital diarrhea is a rare condition in which infants experience very loose, large-volume stools, often starting within the first two to four weeks of life. This severe diarrheacan lead to dehydration, requiring hospitalization. The condition is typically caused abnormalities in the lining of the intestine or defects in how the intestine functions, such as in tufting enteropathy or microvillus inclusion disease. These issues result in poor absorption of nutrients, leading to persistent diarrhea that often requires specializedmanagement.
There are several underlying causes of congenital diarrhea, including malabsorption syndromes, where the intestines cannot absorb complex foods, and congenital transport defects, where the intestines fail to absorb essential salts like sodium, chloride, or potassium, leading to large-volume, loose stools. Structural defects in the intestinal lining or autoimmune conditions that inflame the intestine can also contribute to this condition.
Symptoms of congenital diarrhea include frequent, watery stools, dry mouth, lack of tears when crying, decreased wet diapers, weight loss, and abdominal swelling. Treatment varies depending on the underlying cause, but often includes providing fluids and nutrition through the veins. In severe cases, small bowel or intestinal transplantation may be necessary. Early diagnosis and careful management are crucial for improving outcomes in affected infants.