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The stomach is shifted to the left and turns 90 degrees, the right wall lying dorsally. This results, though, more from a substantial growth of the left wall (later anterior wall) of the stomach and of the fundus than from an active rotation. The relatively short connective tissue bridge of the stomach to the posterior body wall stretches into a long, extended fold, the dorsal mesogastrium. Later the dorsal pancreas and the spleen anlage grow into it. Essential that the differing spurts of growth in the various stomach sections not only lead to shape but also to positional changes is the fact that the duodenum is fixed onto the posterior abdominal wall quite early. From its original intraperitoneal location it assumes a secondary retroperitoneal position (stage 20, ca. 49 days,  20 ). The duodenum is thus a component of the vessel-pancreas-stalk (see: mesenterial relationships of the intestines). The caudal shifting of the entire foregut mentioned at the beginning comes to an end with the formation of the diaphragm and the resulting fixation of the esophagus-cardia passage as well as the formation of the vessel-pancreas-stalk at the level of the duodenum. With this fixation of the stomach at the cardia and pylorus the spurts of growth in the stomach wall now lead only to a horizontal movement of the organ to the left with the above mentioned turn of 90 degrees.
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