Symptoms of patients with Genetic Sucrase-Isomaltase Deficiency/Congenital Sucrase-Isomaltase Deficiency can range from mild to severe chronic, watery, acidic diarrhea, gas, bloating, and abdominal pain.1 Infants do not manifest symptoms of Genetic Sucrase-Isomaltase Deficiency until they begin to ingest sucrose- and starch-containing foods (e.g., juices, solid foods, medications sweetened with sucrose). Chronic, watery diarrhea and failure to thrive are the most common symptoms in infants and toddlers; other consequences include abdominal distention, gassiness, colic, irritability, excoriated buttocks, severe diaper rash due to the acidic diarrhea, dyspepsia, and vomiting. In some societies, notably Greenland Eskimo and some Alaskan Native, a low-carbohydrate, high-protein, high-fat diet may mask symptoms. A small number of patients may require hospitalization for diarrhea and dehydration, malnutrition, muscle wasting, and weakness.2 Patients with confirmed Genetic Sucrase-Isomaltase Deficiency commonly report being examined for Toddler’s Diarrhea/IBS-D, Celiac Disease, Cystic Fibrosis, and food allergies.
In adults, symptoms persist, but may appear to be less severe than those experienced by children. Genetic Sucrase-Isomaltase Deficiency is not a disease that a patient can “outgrow.” In some adults, symptoms may be limited to an increase in bowel frequency, abdominal distention, and flatulence, although episodic watery diarrhea upon ingestion of high levels of sucrose may occur.3 In some patients, diarrhea may alternate with constipation, leading to a misdiagnosis of Irritable Bowel Syndrome (IBS).
As with pediatric patients, the clinical presentation in adults is variable. With the introduction of dietary sucrose, some patients may experience several severe effects from this disease, while others may experience only mild symptoms.