As outlined above small resections of the ileum with an ileo-colic anastamosis will result in lack of the ability of the gut to reabsorb the primary bile salts, which pass into the colon and cause diarrhoea. This is often most marked in the morning due to accumulation at night.
Larger resections with a jejeuno-colic anastamosis will result in a depleted bile salt pool and steatorrhoea.