The intestine, especially the rectum, plays an important role in the human organism. However, it often receives attention only when it has complaints.
What is the rectum?
The rectum (lat. rectum), is part of the large intestine. It is located in the small pelvis between the urinary bladder and the sacrum. Its length varies from individual to individual and averages 15-20cm. The rectum performs important digestive functions. Sometimes, due to malnutrition, an unhealthy lifestyle or serious diseases, the activity of the intestine or even the rectum can be restricted. Symptoms such as pain, blood in the stool, frequently recurring flatulence, diarrhea and constipation should be taken seriously and presented to a doctor. Regular check-ups are among the best prophylactic measures. A balanced diet rich in fiber, as well as adequate fluid intake, are also beneficial to maintaining the health of the rectum.
Anatomy and structure
The rectum forms the last part of the 8-meter-long intestine. It is divided into the upper (ampulla recti) and the lower part (canalis analis). The latter is 2-3 cm long and opens into the anus. The rectum is supplied by the rectal artery and a network of fine blood vessels. A special feature is seen in the veins of the rectum, which have a different outflow. This plays a particularly important role in the spread of metastases. In its structure, the rectum appears as a membranous-muscular tube. Inside is the intestinal mucosa, which is surrounded on the outside by a smooth muscle layer. The end is formed by the so-called tunica serosa. In the lower part of the rectum there is an internal and external sphincter. The internal sphincter, consisting of smooth muscle, works involuntarily. The external sphincter is different. It can be tensed and relaxed by the striated muscles. The rectal artery and the ring muscles seal the rectum. If there is increased pressure from the intestinal contents, bowel movements are triggered. During this, the sphincter muscles slacken and the bowel empties. Pain receptors cannot be found in the rectum but only in the sphincters.
Functions and tasks
In the rectum, fluid is extracted from the food pulp. Important nutrients are filtered out and delivered to the body. The upper part of the rectum, serves solely to hold the feces. The sphincters in the lower part of the rectum additionally regulate bowel movements. Drugs in the form of suppositories pass through the rectum, via the liver, directly into the blood and therefore often work much better than drugs taken orally. Especially for patients with a sensitive stomach, suppositories can be a good alternative.
Diseases
The most common diseases include flatulence, constipation and diarrhea. They are usually harmless and not infrequently caused by a diet too fatty, low in fiber, overweight and increased alcohol and nicotine consumption. However, if they occur more frequently and persist for a long time, a doctor should be consulted in any case. It is not uncommon for them to lead to a chronic intestinal disease such as irritable bowel syndrome, Crohn’s disease or intestinal ulcers. Hemorrhoids, anal fistulas and anal fissures are considered unpleasant and sometimes very embarrassing. However, they can be treated quickly and well. Even inflammations such as enteritis, diverticulitis or collagenous collitis, usually remain without consequential damage to the rectum with the right treatment. Recurrent diseases include irritable bowel syndrome. The rectum can have many diseases. Among the harmless diseases are the benign tumors such as polyps and adenomas. They are usually removed without complications during a colonoscopy. Far more dangerous is rectal cancer. It is considered the second most common cause of cancer-related deaths in Germany. This very aggressive cancer can only be treated well if it is detected in time. Unfortunately, however, there are no clear early symptoms, so that in principle the possibilities of the most diverse examination methods should be used. Palpation, stool tests, colonoscopy, blood tests and virtual colonoscopy are used for diagnosis. A warning sign is blood in the stool. While this can indicate harmless hemorrhoids, it is also often an indication of rectal cancer.
Typical and common bowel diseases
- Crohn’s disease (chronic inflammation of the intestine)
- Inflammation of the intestine (enteritis)
- Intestinal polyps
- Intestinal colic
- Diverticula in the intestine (diverticulosis)
