Syndrome of the small intestine: causes, symptoms, diagnosis, treatment
Last reviewed: 23.04.2024
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The syndrome of the small intestine is malabsorption as a consequence of extensive resection of the small intestine. The manifestations of the disease depend on the length and function of the remaining small intestine, but diarrhea can be severe and characteristic is a malnutrition. Treatment consists of fractional nutrition, taking antidiarrheal drugs and sometimes in complete parenteral nutrition or intestinal transplantation.
Causes of the syndrome of the small intestine
The main causes of extensive bowel resection are Crohn's disease, mesenteric thrombosis, radiation enteritis, malignancy, vomiting and congenital anomalies.
Because the jejunum is the primary site of digestion and the absorption of most nutrients, resection of the jejunum significantly impairs their absorption. As a compensatory reaction, the ileum changes, increasing the length and absorbance of the villi, leading to a gradual increase in the absorption of nutrients.
The ileum is a segment of the small intestine where bile acids and vitamin B12 are absorbed. Severe diarrhea and malabsorption develop during resection of more than 100 cm of the ileum. In this case there is no compensatory adaptation of the remaining jejunum. Consequently, malabsorption of fats, fat-soluble vitamins and vitamin B12 develops. In addition, salts of bile acids that are not absorbed in the small intestine lead to secretory diarrhea. Preservation of the colon can significantly reduce the loss of electrolytes and water. Resection of the terminal part of the ileum and ileocecal sphincter can predispose to the appearance of excessively rapid bacterial growth.
[Symptoms of the syndrome of the small intestine
Immediately in the postoperative period, severe diarrhea develops with significant losses of electrolytes. Patients usually need complete parenteral nutrition and intensive monitoring of fluids and electrolytes (including Ca and Md). Oral intake of iso-osmotic solutions of Na and glucose (similarly to WHO recommended reparation composition) is prescribed gradually in the postoperative period after stabilization of the patient's condition and the amount of stool is less than 2 l / day.
Treatment of the syndrome of the small intestine
Patients after extensive resection (<100 cm of remaining jejunum) and with large losses of fluid and electrolytes need constant complete parenteral nutrition.
Patients who have more than 100 cm of jejunum can achieve adequate digestion by oral ingestion. Fats and proteins in the diet are usually well tolerated, in contrast to carbohydrates, which cause a significant osmotic load. Fractional feeding reduces osmotic pressure. Ideally, if 40% of calories provide fats.
Patients who develop diarrhea after ingestion should take antidiarrheal drugs (eg loperamide) 1 hour before meals. Cholestyramine, taken 2-4 g before eating, reduces diarrhea associated with malabsorption of bile salts. Intramuscular monthly injections of vitamin B 12 are indicated for patients with established vitamin deficiency. Most patients show an additional intake of vitamins, Ca and Mg.
Gastric hypersecretion can develop, which leads to deactivation of pancreatic enzymes; so most patients are prescribed H 2 -blockers or proton pump inhibitors.
Small bowel transplantation is indicated in patients who can not permanently use full parenteral nutrition and who do not compensate for digestive processes.