descending colon

anatomy

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Last updated

June 25, 2026

Quick Summary

The descending colon is a segment of the large intestine that extends from the transverse colon down the left side of the abdomen to the sigmoid colon. Its primary functions include lubricating waste products, absorbing remaining fluids and salts, and storing waste until elimination. The inner wall is a mucous membrane that secretes mucus and absorbs fluids, while deeper muscle layers of circular and longitudinal muscles propel waste. Disorders associated with the colon include constipation, diarrhea, and inflammation like colitis. The sigmoid colon, the final section before the rectum, stores fecal waste and is named for its S-shape.12

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colon
…down the left side (descending colon) and then loops (at the sigmoid flexure, or sigmoid colon) to join the rectum. The purpose of the colon is to lubricate waste products, absorb remaining fluids and salts, and store waste products until they are ready to be passed from the body.…
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…down the left side (descending colon) and then loops (at the sigmoid flexure, or sigmoid colon) to join the rectum. The purpose of the colon is to lubricate waste products, absorb remaining fluids and salts, and store waste products until they are ready to be passed from the body.…
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human digestive system
Anatomy
The descending colon passes down and in front of the left kidney and the left side of the posterior abdominal wall to the iliac crest (the upper border of the hipbone). The descending colon is more likely than the ascending colon to be surrounded by peritoneum.
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The descending colon passes down and in front of the left kidney and the left side of the posterior abdominal wall to the iliac crest (the upper border of the hipbone). The descending colon is more likely than the ascending colon to be surrounded by peritoneum.
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