Acquired (secondary) S-I Deficiency

Genetic defects in the gene coding for the sucrase-isomaltase enzyme (see CSID Primer) or damage to the small intestine due to injury, surgery or other diseases can lead to complete or nearly complete absence of sucrase activity. In the latter case this is known as secondary or acquired sucrase-isomaltase deficiency.

Any disorder affecting the absorption or luminal processing of ingested nutrients causes the clinical syndrome of malabsorption. Malnutrition, infection, or allergic or autoimmune reactions affecting the gut can cause mucosal damage and bacterial overgrowth, resulting in secondary malabsorption.

Many patients with malabsorption syndromes present with chronic diarrhea and weight loss. Diarrhea that lasts more than 2-4 weeks, despite simple interventions, raises the suspicion of a malabsorption syndrome.

Sucrose malabsorption is caused by a malfunction in, or absence of, the machinery required to process and transport the nutrients across the intestinal mucosa into the systemic circulation. Malabsorption may also be caused by an overabundance of the same nutrients. Either a congenital abnormality in digestive physiology or, more commonly, a secondarily induced absence or reduction in the digestive apparatus causes malabsorption.

Damage or atrophy of the intestinal mucosa resulting from malnutrition or any other cause reduces the intestinal absorption area and the number of intestinal transport proteins and brush border enzymes.

Toddler's diarrhea accounts for approximately 7.5% of referrals to pediatric gastroenterologists, and it is the most common malabsorption syndrome of childhood that is not associated with infection. Because of the difficulty in diagnosing CSID and the similarity of symptoms to other small intestinal conditions, the diagnosis can easily be missed. Allergic gastroenteropathy, cystic fibrosis, celiac disease, severe viral gastroenteritis, lactose intolerance, glucose-galactose intolerance, dyspepsia or other causes of intractable diarrhea are often considered in diagnosis. Mild steatorrhea is commonly used to support these diagnosis. Other conditions such as IBS, Autoimmune enteropathy, Primary intestinal lymphoma, Eosinophilic gastroenteritis, HIV enteropathy with wasting syndrome, GVHD, and Short bowel syndrome may all result in a deficiency of sucrase-isomaltase enzyme, either temporarily or permanently.

The effects of Sucraid® in patients with secondary (acquired) disaccharidase deficiencies have not been evaluated