For the Intraperitoneal organs remember SALTD SPRSS (Pronounced Salted Spursss):

S = Stomach

A = Appendix

L = Liver

T = Transverse colon

D = duodenum (only the 1st part, though)

S = Small intestines

P = Pancreas (only the tail though)

R = Rectum (only the upper 3rd)

S = Sigmoid colon

S = Spleen

For retroperitoneal, just remember SADPUCKER:

S = suprarenal glands

A = Aorta and IVC

D = Duodenum (all but the 1st part)

P = Pancreas (all but the tail)

U = Ureter and bladder

C = Colon (ascending and descending)

K = Kidneys

E = Esophagus

R = Rectum (Lower two-thirds)

For secondarily retroperitoneal remember ‘Pussy Cat Dolls“:

P = Pancreas

C = Colon (only ascending and descending)

D = Duodenum (only parts 2-4)