1 — Urinary bladder; 2 — Appendix; Vermiform appendix; 3 — Caecal fossa; 4 — Meso-appendix; 5 — Retrocaecal recess; 6 — Caecum; 7 — Caecum fold; 8 — Ileocaecal fold; 9 — Ascending colon; 10 — Ileum; 11 — Root of mesentery; 12 — Sigmoid colon; 13 — Descending colon; 14 — Sigmoid mesocolon; 15 — Intersigmoid recess; 16 — External iliac vessels; 17 — Parietal peritoneum; 18 — Ureter; 19 — Postvesical
fold; 20 — Rectum