Human Anatomy - Kotsan I. Y. 2009

Splanchnology
Digestive System
Age-related characteristics of the large intestine

The length of the newborn's Large Intestine averages 63 cm. Intestinal sacculations (haustra) and omental Appendices ( epiploic appendages) are absent in newborns. Haustra begin to appear at six months of age, and epiploic appendices during the second year of life. The ileocecal orifice in newborns is triangular or ring-shaped and remains patent. In children older than one year, it becomes slit-like. The ileocecal valve appears as small folds. The opening of the vermiform Appendix is also patent in newborns. The formation of the valve closing the entrance to the appendix begins with the appearance of a fold near the appendiceal orifice at the end of the first year of life. The mucous membrane of the vermiform appendix in newborns contains numerous lymphoid follicles that form Aggregated lymphoid nodules. They reach their maximum development at 10–14 years of age.

The ascending colon is poorly developed in newborns. During adolescence and youth, it acquires the structural characteristics typical of an adult. Its maximum development is observed at 40–50 years of age.

The transverse colon in newborns has a very short mesocolon (up to 2 cm). By one and a half years of age, the width of the mesocolon reaches 5–8.5 cm. In infants during their first year of life, the length of the transverse colon is 26–28 cm. By 10 years of age, it reaches 35 cm. The transverse colon attains its greatest length in elderly individuals.

The descending colon in newborns is about 5 cm long. By one year of age, its length doubles; by 5 years, it measures 15 cm; and by 10 years, 16 cm. Thereafter, its length continues to increase, reaching its maximum in old age.

The sigmoid colon in newborns is approximately 20 cm long. By 10 years of age, its length increases to 38 cm. After 60–70 years, the sigmoid colon undergoes atrophy due to the thinning of its walls.

The rectum in newborns is cylindrical in shape, lacking an ampulla and flexures, and its folds are poorly defined. Its length is 5–6 cm. The Formation of the rectal ampulla is completed by the age of 7, and the flexures after 8 years. Anal columns and sinuses are well developed in children. Significant growth of the rectum occurs after 8 years of age. By adolescence, the rectum reaches a length of 15–18 cm.



Last update: 08/08/2026

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