How does IBD affect digestion and absorption?
Ulcerative Colitis: Ulcerative colitis only affects the large bowel and therefore does not affect the digestion or absorption of most nutrients. However, it can interfere with water absorption, leading to diarrhoea. Blood and protein can also be lost from the inflamed lining of the bowel. Crohn’s Disease: If the ileum is affected there may be decreased absorption of Vitamin B12 and bile salts. Lack of bile salts may impair absorption of fat. If the entire small bowel is affected (or if a large amount of small bowel has been removed) absorption of most nutrients will be compromised. In some patients the disease causes narrowing of the small bowel resulting in pain and discomfort after eating. If Crohn’s disease involves the large bowel water absorption is affected, resulting in diarrhoea. Why do nutritional problems occur in IBD? Poor Food Intake Poor food intake is the commonest cause of inadequate nutrition in IBD and may be due to poor appetite, restrictive diets or reducing food int
