The prevalence of short bowel syndrome has increased by more than 2 fold in the last 40 years. It is classified as a rare disease by the European Medicines Agency. Outcomes depend on the amount of bowel remaining and whether or not the small bowel remains connected with the large bowel. Signs and symptoms
The symptoms of short bowel syndrome can include:
Abdominal pain
Diarrhea and steatorrhea (oily, bulky stool, which can be malodorous)
Fluid depletion
Weight loss and malnutrition
FatiguePersons with short bowel syndrome may have complications caused by malabsorption of vitamins and minerals, such as deficiencies in vitamins A, D, E, K, B9 (folic acid), and B12, calcium, magnesium, iron, and zinc. These may appear as anemia, hyperkeratosis (scaling of the skin), easy bruising, muscle spasms, poor blood clotting, and bone pain. Causes
Short bowel syndrome in adults and children is most commonly caused by surgery (intestinal resection). In those who undergo intestinal resection, approximately 15% eventually develop small bowel syndrome (75% of those due to 1 large resection and 25% due to multiple separate intestinal resections). This surgery may be done for:

Crohns disease, an inflammatory disorder of the digestive tract
Mesenteric ischemia, embolic or thrombotic events that may occur in the arteries or veins that supply or drain the intestines respectively, leading to disruption of blood supply to the intestines and ischemia.
The resection of the ileum leads to a malabsorption of vitamin B12, bile acids and the fat soluble vitamins A, D, E and K. Loss of the distal ileum also leads to loss of inhibitory hormones; leading to gastric hypersecretion, intestinal hypermotility (decreases in the intestinal transit time) leading to secretory diarrhea and macronutrient, micronutrient, vitamin and mineral deficiencies. Loss of the ileocecal valve leads to small intestinal bacterial overgrowth(SIBO) as bacterial flora normally found in the large intestines migrate proximally and colonize the small intestines leading to further malabsorption. SIBO leads to malabsorption as the bacteria colonizing the small intestine metabolize nutrients, directly competing with the intestinal absorption of nutrients. The bacteria colonizing the small intestines in SIBO may also cause bile acid deconjugation leading to malabsorption of lipids.In a process called intestinal adaptation, physiological changes to the remaining portion of the small intestine occur to increase its absorptive capacity. These changes usually take place over 1-2 years. These changes include:

Enlargement (increased diameter) and lengthening of the villi found in the lining
Increase in the diameter of the small intestine
Slow down in peristalsis or movement of food through the small intestine (an increase in the transit time) to increase the time available for nutrient absorptionOsteoporosis is a very common comorbidity in people with short bowel syndrome who are on parenteral nutrition, with an estimated prevalence of 57-67%. The contributing factors to the osteoporosis include malnutrition, vitamin D deficiency due to malabsorption and vitamin D deficiency due to scarce sunlight exposure due to chronic disability.