On contrast radiography which among the following is FALSE:

First pa of the duodenum is visible as a triangular shadow on barium studies and is known as duodenal cap. Small intestine contains mucosal folds known as plicae circulares that are visible on barium studies and help in the distinction between small intestine and colon. Colon instead can be identified by presence of haustrations. Valvulae conniventes are more prominent in the jejunum giving the 'feathery appearance' on barium and reduced distally giving a 'featureless' appearance of distal ileum.