If the distal 2/3rd of the ileum is including the ileocecal valve is resected, significant abnormalities of absorption of bike salts and Vitamin B12 may occur resulting in diarrhoea and anaemia. These abnormalities occur even though only 25% of total length of the small bowel is removed Proximal bowel resection is better tolerated than distal resection because the ileum can adapt and increase its absorptive capacity more efficiently than jejunum Ref: Sabiston 20th edition Pgno : 1171