In this visual medical lecture Dr. Aizaz from MedicoVisual explains the midgut rotation and development of midgut
00:00 intro to midgut, foregut and hindgut
02:46 Physiological Umbilical Hernia of the midgut
04:15 What is Primary Intestinal Loop
06:36 Formation cecal bud or cecal swelling
08:58 Pre-arterial and Post-arterial limb of intestinal loop of midgut
10:24 Initial 90 degrees anticlockwise rotation
13:49 Remaining 180 degree anticlockwise rotation during retraction phase
17:28 Retraction of midgut intestinal loops
18:57 Downward movement of ascending colon into the lower abdomen
22:00 Complete 3D Animation of Midgut Rotation
22:19 Fixation of Intestines (Ascending colon's peritoneum)
25:00 Formation of Cecum and Appendix from the cecal bud
Initially the midgut is very small in length and almost all of it is connected directly and broadly with the vitelline duct. However, as it grows in length, it forms a loop or coil, which at it’s apex, is connected to the vitelline duct. As this primary midgut loop (also called primary intestinal loop lengthens further, it is impossible to keep this loop resided within the tiny abdomen of the fetus. The abdomen is small and there is a huge liver sitting in there as well. So, this loop has to herniate out of he abdomen and finds a temporary spot within the umbilical cord, which itself lies within the extraembryonic celom. The loop will later come back into the abdomen, and we will see that later. This normal and temporary herniation of primary intestinal loop into the umbilical cord is called Physiological hernia.
The midgut is supplied by the superior mesenteric artery, a branch of dorsal aorta. The foregut is supplied by the celiac trunk and hindgut by the inferior mesenteric artery.
The superior mesenteric artery’s main stem terminates at the apex of the primary intestinal loop. The cranial limb of this loop is more appropriately called pre-arterial limb and caudal limb is called post-arterial. I said, “more appropriately called”, because later we will see that this coil will rotate around the main stem of superior mesenteric artery. As this will happen, the cranial and caudal demarcation will longer hold true. (For example, with the first 90-degree anticlockwise rotation, both of the limbs will lie in the same plane, and it would be hard to demarcate which one is cranial and which one is caudal).
While inside the umbilical cord, few changes occur within both of the limbs of this loop. The Pre-arterial limb (or cranial limb) will form most of the small intestines viz., a part of duodenum, jejunum and a part of ileum. Since the aim of life of small intestine is to absorb nutrients, it wants to absorb as much nutrients as possible. For this purpose, the small intestines must be quite longer to fetch every possible particle of the nutrients from the food. So naturally the prearterial limb lengthens more as compared to the postarterial limb. Therefore, it forms a convoluted appearance.
The postarterial limb forms the remaining part of the ileum, cecum, ascending colon and proximal 2/3rd of the transverse colon. At termination of primordial ileum, a conical swelling appears which will later develop into the cecum. This swelling is called the cecal bud.
 
Rotation of midgut loop:
Within the extraembryonic celom and umbilical cord, the primary intestinal loop takes it first 90 degrees turn anticlockwise around the axis of superior mesenteric artery. Now both of the limbs lie in the same horizontal plane.
After this initial 90-degree rotation, this loop undergoes another 180 degrees anticlockwise rotation.
Now the prearterial limb is on the left and the post-arterial limb is on the right side.
The proximal part of the postarterial limb between the cecal bud and the origin of vitelline duct forms the distal part of ileum. The cecal bud grows into cecum which cranially continues as ascending colon. The part of postarterial limb that is distal to cecal bud and is continuous with the hindgut, forms the ascending colon and proximal 2/3rd part of the transverse colon.
Actually the first 90 degree anticlockwise rotation occur within the umbilical cord while the remaining 180 degrees happens as the loop is retracted back into the abdomen, as it has grown enough. However, for the sake of simplicity and ease of explanation I have shown the complete 270 degrees rotation within the umbilical cord.
So, the loops are retracted back into the abdomen. By this time, the vitelline duct is obliterated, and it loses its connection with the intestine.
Here you can see that the cecal bud is into the upper right quadrant of the abdomen. It should be at the right lower quadrant.