Where is the female colon located?

The duodenum of the human body is actually inside the anus. It is connected to the anus and above it is part of the sigmoid colon. It is the last section of the intestine. Because it is relatively vertically downward, it is called the duodenum. The adjacent relationship between the duodenum and the small bone 0 pelvic bone of the human body's internal organs is different in men and women. In front of the male duodenum are the duodenal fossa, seminal vesicle, ampulla of the vas deferens, male prostatitis, and pelvic part of the urethra; in front of the female duodenum are the uterus, female vagina, posterior female vaginal fornix, duodenourenteral fossa, and uterine female vaginal septum. Therefore, when clinical medicine professionals perform digital rectal examinations, they can palpate male prostatitis and seminal vesicles or uterus and female vagina through the anus.

Its course is not straight but several bends. It has three transverse wrinkles, two of which are on the left and one on the right, with different heights. Viewed from below, the three wrinkles overlap each other, surrounding the duodenum and carrying fecal stones.

The section of the duodenum near the anus expands into the duodenal ampulla, which contains 6 to 10 vertical wrinkled walls called anal columns, and above the anal columns there is a venous plexus. The duodenum ends at the anus. The anus includes an external anal extension and an internal anal extension. The anal protrusion is a voluntary muscle and belongs to the vulvar muscle. The internal anal dilatation is made up of extremely thick intraintestinal circular muscle, which is a smooth muscle. Its function is to completely eliminate the waste remaining in the anal canal when defecation is about to take place.

The duodenum refers to a section of the intestine that starts from the sigmoid colon just in front of the third lumbar intervertebral disc, descends along the front of the sacrum and coccyx, crosses the pelvic diaphragm and transitions to the anal canal. The duodenum is a section of the digestive tract located below the pelvis, with a total length of 10 to 14 cm. The duodenum is bent, forming two obvious bends in the sagittal plane, namely the sacral duodenal flexure and the pudendal duodenal flexure. There are also three bends protruding to the side on the coronal plane, but they are unstable. Generally, the very large one in the middle bulges to the left, and the upper and lower two bulges to the right. When clinical medical professionals perform colonoscopy and sigmoidoscopy, they should pay attention to such bends to avoid harming the intestinal tract.