Regarding contrast radiography which among the following is FALSE?

The first pa of the duodenum has the duodenal cap or bulb and not the distal pa. The first pa of the duodenum is visible as a triangular shadow on barium studies and is called duodenal cap. The small intestine contains mucosal folds known as plicae circulares or valvulae conniventes that are visible on barium studies and help in the distinction between small intestine and colon. Valvulae conniventes are more prominent in the jejunum giving the 'feathery appearance' on barium. These mucosal folds are gradually reduced distally giving a 'featureless' appearance of distal ileum. In the colon, mucosal pattern is best evaluated with double contrast examination. Normal colon mucosa is thin, smooth and straight essentially featureless except for the haustral markings. In the rectum, there are three prominent folds called the valves of Houston. In a paially collapsed rectum colums of Morgagni may be seen in the distal poion.