What Is the Anatomy of the Colon?

The sigmoid colon refers to the descending colon starting from the left iliac crest and turning into the pelvic cavity along the left popliteal fossa. The length of the sigmoid colon is "B" -shaped, and the large intestine with a length of about 40 cm that extends from the rectum to the third sacral vertebra is called the sigmoid colon. A part of the colon is connected to the descending colon at the left sacral plane and continues to the rectum to the third sacral vertebra. It is located in the lower left abdomen and the small pelvis, and is curved in a "B" or "S" shape. The thick ones can be touched in the left lower abdomen, and they are smooth and slightly hard barrel-shaped. The thickness is like a candle. Children vary in thickness depending on their age, without tenderness. The sigmoid colon can develop inflammation and tumors, which are rare in children. If palpation is not possible, a sigmoidoscopy can be performed.

The sigmoid colon refers to the descending colon starting from the left iliac crest and turning into the pelvic cavity along the left popliteal fossa. The length of the sigmoid colon is "B" -shaped, and the large intestine with a length of about 40 cm that extends from the rectum to the third sacral vertebra is called the sigmoid colon. A part of the colon is connected to the descending colon at the left sacral plane and continues to the rectum to the third sacral vertebra. It is located in the lower left abdomen and the small pelvis, and is curved in a "B" or "S" shape. The thick ones can be touched in the left lower abdomen, and they are smooth and slightly hard barrel-shaped. The thickness is like a candle. Children vary in thickness depending on their age, without tenderness. The sigmoid colon can develop inflammation and tumors, which are rare in children. If palpation is not possible, a sigmoidoscopy can be performed.

Chinese name

Sigmoid colon

Foreign name

sigmoid colon

Category

organ

Location

Colon between descending colon and rectum

Overview of the sigmoid colon

It is part of the colon. B-shaped curve, from the left condyle to the descending colon, continued to the rectum at the upper edge of the 3rd sacrum. Mesangium varies greatly in length, shape, and location. The sigmoid sometimes protrudes to the upper right, and sometimes descends into the pelvic cavity and contacts the pelvic organs. The sigmoid colon is attached to the side wall of the large pelvis through the mesentery. The sigmoid colon is prone to intestinal torsion when it suddenly changes position due to its long mesentery. Because the contents of the intestine tend to stagnate here, it can form faeces, which can be touched when it is palpated. Multiple tumor sites.

The upper part of the descending colon and the lower part of the colon are connected to the rectum. Adults are about 40 to 45 cm long, have mesangial fixation, have large mobility, and are the most common sites of diverticulum and tumors. The sigmoid colon is also called the sigmoid colon. A part of the colon is connected to the descending colon. It forms a "B" shape near the left sacrum and connects the lower rectum. Sigmoid colon cancer: a type of colon cancer that occurs in the sigmoid colon.

Anatomy of the sigmoid colon

The sigmoid colon is a section located between the descending colon and rectum. This section of the intestine is often named "B" because it is curved. At about the height of the left condyle, it moves in phase with the descending colon. The bending direction of the sigmoid colon initially extends inward and downward to the vicinity of the pelvic entrance. At the inner edge of the psoas major muscle, it turns to the upper and inner sides to form the first bend. The position of this bend is extremely unstable, and it is mostly in the pelvic cavity. The bowel passes inward and upward past the bifurcation of the common iliac artery and turns down again, forming a second bend. The position of the bend is also not fixed, and may be located to the left of the midline. It descends from the second bend to the height of the 3rd sacrum and continues to the rectum.

The sigmoid colon is an internal peritoneal organ. It is completely surrounded by the peritoneum and forms the sigmoid mesentery. This mesangium connects the sigmoid colon to the left popliteal fossa and the posterior wall of the small pelvis. The attachment line of the mesangial root is often in the shape of a herringbone. The sigmoid colonic mesentery is longer in the middle of the intestinal canal, and it gradually becomes shorter and disappears as it extends upward and downward. Therefore, the sigmoid colon and the descending colon and rectal phase transitions are fixed and cannot be moved. The middle section has a larger range of activities. The length of the sigmoid mesangium is not very constant, and it is generally longer in children. Sometimes if the mesangium is too long, it may be one of the factors that cause the sigmoid torsion.

Sigmoid and sigmoid-related diseases

Sigmoid colitis

Idiopathic inflammatory bowel disease includes Crohn'sdiseae (ileum, segmental enteritis, granulomatous colitis) and ulcerative colitis. Focal, small intestine and / or colon lesions that often pass through the entire intestinal wall are accompanied by extra-intestinal manifestations of Crohn's disease. Inflammation of the diffuse superficial colonic mucosa extending from the rectum to the proximal end is characteristic of ulcerative colitis. Although both diseases can be accompanied by diarrhea, bloody diarrhea is more common in ulcerative colitis. Inflammatory bowel disease is characterized by unpredictable relapses. Intermittent infections, the use of antibiotics or non-steroidal anti-inflammatory drugs, or excessive stress increase the number and extent of attacks.

Individualized medical treatments including diet control, nutrition and emotional support, antidiarrheal and anti-inflammatory drugs often control ulcerative colitis and clonal disease, despite a tendency to relapse.

Surgical indications for ulcerative colitis are serious complications, the most powerful medical treatments still respond poorly, or excessive drug side effects (eg, steroids). Colectomy and ileostomy or colectomy and ileal anal anastomosis for radical ulcerative colitis. Rectal mucosal resection and ileal storage bags require many months of physiological adjustments. However, most patients retain the ability to control their liquid stools 4 to 8 times a day. Many patients have reduced bowel movements with antidiarrheal drugs and / or psyllium fiber supplementation. Sacks (inflammation in the ileal pouch) occur in about 15% of cases and generally respond to metronidazole for 1 course of treatment.

Surgical indications for Crohn's disease are persistent intestinal obstruction, abscesses, uncontrollable bleeding, and perforation. Severe colon disease may require a total colectomy and an ileostomy. However, the recurrence rate after bowel resection and anastomosis is about 80%.

Sigmoid sigmoid lengthy

Digestive diagnosis and treatment of sigmoid colon: The length of the colon can be verbose, and it is generally considered that 35% to 40% of the length of the standard value can be diagnosed as colostomy. The range of sigmoid activity reaches the upper right or lower right abdomen. Versatility. In this case, the length of the sigmoid colon and its mesentery was not measured during the operation, and the length of the postoperative pathological measurement was 37 cm, which is related to the shortening of the length after formalin immersion. In addition, whether there are large individual differences in the length of each part of the colon is worth further the study. The diagnosis of lengthy colon is mainly based on the history of the disease and barium enema. The history of this case is typical. The barium enema shows that the spleen and bowel are long, suspended and formed tortuous. The sigmoid colon forms several twists and turns around the pelvic cavity. Obvious colonic bag-shaped, sausage-like, mucous membrane meets the spleen and colon twisted and folded, no sacral rectal separation. Sausage-like changes in the colon are associated with chronic fatigue injury caused by long-term difficulty in defecation. The barium enema can intuitively reflect the lengthy condition of the colon, but it must also be considered in conjunction with other clinical data. In this case, the type III colon is considered to be redundant, and the length of the colonic liver curvature and spleen curvature is slightly longer during operation. The lengthy criteria are therefore diagnosed as sigmoid lengthy and treated accordingly. Colonoscopy has little significance for lengthy diagnosis, and the judgment of colonic lesions is not accurate enough (in this case, the colonoscopy reports 90 cm from the scope to the ileocecal area), but other lesions can be ruled out, such as colonism and colon cancer. .