Large intestine

Synonyms in a broader sense

Colon, interstitium grassum, colon, rectum, rectum (rectum, rectum), appendix (caecum), appendix (Appenedix vermiformis)

English: colon


As the last section of the digestive tract, the large intestine connects to the small intestine and, with its 1.5 meters length, frames the small intestine on almost all sides. The main task of the large intestine is to remove (resorb) the fluid and the various minerals (electrolytes) in food from the intestinal contents and thus to thicken the stool. The large intestine is populated with bacteria (microflora) that perform important functions for the large intestine and thus for the organism.

Further information on the anatomy of the abdominal cavity can be found here: Abdominal cavity

Figure large intestine

Figure large intestine: location of the digestive organs in the body cavity (large intestine-red)
  1. Colon, ascending part -
    Ascending colon
  2. Appendix - Caecum
  3. Appendix -
    Appendix vermiformis
  4. Right colon bend -
    Flexura coli dextra
  5. Large intestine, transverse part -
    Transverse colon
  6. Left colon bend -
    Flexura coli sinistra
  7. Large intestine, descending part -
    Descending colon
  8. Large intestine, s-shaped part -
    Sigmoid colon
  9. Rectum - Rectum
  10. Bulges of the
    Colon Wall -
    Haustra coli
  11. Liver - Hepar
  12. Stomach - Guest
  13. Spleen - Sink
  14. Gallbladder -
    Vesica biliaris
  15. Small intestine -
    Intestine tenue
  16. Esophagus -

You can find an overview of all Dr-Gumpert images at: medical illustrations

Structure and length of the large intestine

The colon starts behind the Bauhinschen flap (Ileocecal valve), which shields the small intestine from the colon colonized by bacteria. Behind is that appendix (Cecum, Caecum), which, as the name suggests, ends blindly in the abdomen. The appendix is ​​about 7 cm long and has an appendage, which because of its appearance Appendix vermiformis is called. The appendix is ​​on average 9 cm long, but its length is subject to strong individual fluctuations. The position of the appendix is ​​very variable, which is why appendix pain does not always appear immediately.
The length of the entire colon also varies.


Not infrequently, however, the pain is projected in the so-called ´Appendicitis` (appendicitis) to a point on the lower right abdominal wall, den McBurney Point. This point lies between the right anterior upper iliac spine (spina iliaca anterior superior) and the navel.

The length of the colon varies from person to person. E.g. Age, gender, genetic makeup and height all play a role. However, it can roughly be said that a normal human colon is between 1.20 and 1.50 meters is long.
The individual sections also differ in their length: in the right half of the abdomen, it is around 20-25cm long Ascending colon (ascending colon). At the height between the 12th thoracic vertebra and the 2nd lumbar vertebra, the approximately 40cm long runs horizontally to the left side Transverse colon (horizontal colon). It closes with 20-25cm that Descending colon (descending colon), which is in the Sigmoid colon (S-shaped large intestine) with a length of about 40 cm. The large intestine forms a frame around the much longer one Small intestine (circa 3.75m). Furthermore, both the small ones count appendix with the appendix, as well as that about 15-20 cm long rectum to the colon.

Layer structure and structures of the colon wall

Structure of the digestive system

There are certain structures that characterize the large intestine. The macroscopically visible, colon-specific Taenien, are three longitudinal strips approx. 1 cm wide, on which the longitudinal muscles are somewhat compressed. The so-called House doors are also typical of the macroscopic appearance of the large intestine. They arise through periodic contractions of the circular muscles, so that constrictions can be separated from bulges at a distance of a few centimeters. They are also typical of the large intestine (colon) Fat appendages (Appendices epiploicae) hanging from the taenias. For surface enlargement there are closely spaced 0.5 cm deep in the large intestine Crypts (Glandulae inetstinales). The villi, which are typical of the small intestine and which are required for food absorption, are no longer needed in the large intestine. Also, the colon is characterized by many Goblet cells and especially long Microvilli, which represent the micro-relief of the mucous membrane.

The wall structure of the mucous membrane of the large intestine largely corresponds to that of the other sections of the digestive tract.

  • The inside of the colon wall is lined with mucous membrane (Tunica mucosa), which are divided into three sub-layers. The top layer is a cover fabric (Lamina epithelialis mucosae, epithelium). In the covering tissue of the large intestine, a particularly large number of cells are stored which are filled with mucus, which they periodically release into the interior of the intestine and thus ensure the ability of the intestinal contents to slide. This is called Goblet cells. The next sub-layer is a shift layer (Lamina propria mucosae), which contains a particularly large number of lymphocytes and lymph follicles for the immune function of the intestine. Then there is a very narrow layer of natural muscles (Lamina muscularis mucosae), which can change the relief of the mucous membrane.
  • Another loose shifting layer follows (Tela submucosa), which consists of connective tissue and in which a network of blood and lymph vessels runs, as well as a nerve fiber plexus known as Submucosal plexus (Meissner's plexus) referred to as. This plexus represents the so-called Enteric nervous system and innervates (regulates bowel activity) the bowel independently of the Central nervous system (CNS).
  • The following colon muscle layer (Tunica muscularis) is divided into two sub-layers, the fibers of which run in different directions: First, an inner layer Spinal muscle layer (Circular stratum) caused by periodic contractions typical of the large intestine House doors (see above) forms. The outer Longitudinal muscle layer (Stratum longitudinal) is at the so-called Tenien (see above) somewhat crowded together. Between this ring and the longitudinal muscle layer runs a network of nerve fibers, the Myenteric plexus (Auerbach plexus), which innervates these muscle layers. These muscles ensure the wave-like movement of the intestine (Peristaltic movement).
  • Another shift shift follows (Tela subserosa).
  • The conclusion is a coating of the peritoneum (peritoneum) that lines all organs. This coating is also called Tunica serosa.

"Internal organs" illustration

  1. Thyroid cartilage / larynx
  2. Windpipe (trachea)
  3. Heart (cor)
  4. Stomach (gaster)
  5. Large intestine (colon)
  6. Rectum
  7. Small intestine (ilium, jejunum)
  8. Liver (hepar)
  9. lung

Function and tasks

In the large intestine, the intestinal contents are primarily thickened and mixed. In addition, the large intestine is responsible for the urge to defecate and defecate.

The physician understands motility to be the totality of Movements of the colon. They serve to thoroughly mix the food, but also to transport the intestinal contents towards the rectum:

a) Mixing movements
They occupy the majority of the movements in the colon and are at a maximum frequency of 15 movements / minute rather slowly. In a normal and healthy adult, the food pulp lingers in between 20 and 35 hours in the colon. However, this time fluctuates considerably, so that depending on the food components and mental state, the length of stay can increase to up to 70 hours! The vigorous mixing of the intestinal contents ensures sufficient resumption (absorption) important nutrients and water.

b) Transport movements
Transport movements in the large intestine are rather rare. Instead, they appear after meals as so-called "Mass movements" on. They transport the intestinal contents into the rectum and are associated with an urge to defecate if the intestine is sufficiently full. This is often followed by defecation with a total daily amount of stool of around 100-150g per day.

2. Recovery
Basically, the large intestine is more likely to play a role in re-absorbing nutrients and water subordinate Role. A large part of this happens in the small intestine, so that the feces are only finally thickened and covered with a slippery layer of mucus.

3. intestinal flora
Our large intestine is naturally home to a multitude of them bacteriawhich perform indispensable functions in digestion. It is estimated that there are around 1011-1012 bacteria per milliliter of intestinal content! They split undigested, vegetable fibers (e.g. cellulose) and produce important nutrients such as Biotin (Vitamin B7) or vitamin K.

Stool reflex (defecation reflex)

When the rectal ampoule fills with feces, the intestinal wall is stretched at this point and the filling level is measured by receptors (feelers). The Stretch receptors send signals to the interconnection systems in the Spinal cord and brain. When stool is “allowed” by the brain, a signal is sent to Relaxation of the external anal sphincter sent and the stool (defecation) initiated.

Pain in the colon

Pain in the colon can have different causes. The most common are:

Appendicitis (Appendicitis)
Popularly the inflammation is the Appendix (Latin: appendix vermiformis) also known as appendicitis. Strictly speaking, however, this term is incorrect because it is not appendix (Latin: Caecum), but only its appendage is inflamed! At the beginning of the illness, those affected typically feel a dull, non-localizable pain in the Middle or upper abdomen. Within the first 8-12 hours, the pain migrates to the right lower abdomen. There it increases in intensity over time, so that patients suffer from severe, often burning pain. The Mc-Burney point and the Lanz point are particularly sensitive to pain.

Diverticula are understood to be Protuberances the colon wall outwards.As a rule, they do not cause any pain and therefore often go unnoticed for a long time. It is now known that the risk of colon cancer increases with size. Due to various causes, e.g. difficult to digest food components, the mucous membrane of the diverticulum can be injured. This is how germs get in and cause Inflammation. In the worst case scenario, it can be an inflamed diverticulum set out (perforate) and such a dangerous one Peritonitis (Latin: peritonitis) cause. In over 90% of cases, the diverticula are found in the Sigmoid colon. Therefore, sufferers experience diverticulitis left-sided Pain in the lower abdomen.

Irritable bowel syndrome
Irritable bowel syndrome (also called irritable bowel syndrome, irritable bowel syndrome or functional bowel problems) is a collective term for chronic Abdominal complaints that cannot be explained by other clinical pictures. Patients suffer from pain in the entire Abdominal area, constipation, Diarrhea, gas and bloating. Since there is no permanent organic damage in this disease, it is initially not "dangerous". Instead, a close connection between mental discomfort (stress, anger, etc.) and irritable bowel syndrome has been proven. Those affected very often feel a high level of suffering.


Abdominal pain can indicate a disease of the colon. A distinction is made between cramp-like, stabbing, burning, pressing, colicky and pulling abdominal pain. Heat applications (e.g. hot water bottle) can provide relief in many cases.

Under diarrhea (Diarrhea) means repeated occurrence of too liquid stools and is no independent disease, but only a symptom. For example, it can often be observed in inflammation of the colon. Uncomplicated courses usually do not require therapy. However, if diarrhea persists over a longer period of time, the strong loss of fluids and minerals must be compensated for (e.g. with infusions).

constipation (Constipation) is one of the common diseases of our time. In addition to e.g. Improper nutrition, lack of fluids and exercise or metabolic disorders can cause adhesions, diverticula or tumors in the colon to cause constipation. The therapy depends on the cause of the problem. Increased fluid intake is always advisable.

Common illnesses

To the most common intestinal diseases counts among other things Inflammation of sacs in the intestinal wall, the so-called. Diverticulitis. If such diverticulitis occurs more often, one speaks of a so-called. Diverticulosis. It is believed that this inflammation is caused by Stool or build-up of food Put pressure on the already thin wall of the diverticulum. So can bacterial Infections in surrounding connective tissue and in this way one Peritonitis trigger. With 95% diverticulitis occurs at a distance most common in the sigmoid on - the S-shaped area of ​​the colon, which is in the pool runs. Diverticulitis manifests itself in the classic triad of symptoms Pain in the left lower abdomen, fever and one increased white blood cell count. Therapy is usually conservative (i.e. no surgical interventions), characterized by the administration of Antibiotics and a strict one diet.

Another common condition is that Appendicitis, the so-called. appendicitis. It can be by naturally existing Components of the intestinal flora or pathogensthat over the blood den Intestines reach, be evoked. The symptoms of appendicitis are mostly diffusei.e. not clearly assignable. She expresses herself through nausea, Vomit and Pain in the upper abdomen.

Another common colon disease are the Polyps. They are thickened growths the innermost Intestinal liningthat protrude into the intestinal lumen. Polyps are benign tumors and thus harmless in itselfHowever, there is an increased risk of them in the long run Colon cancer ulcers degenerate.
A serious bowel disease that not quite as often like the above is is Crohn's disease (named after the American gastroenterologist Burril Crohn). Crohn's disease is one inflammatory disease of the gastrointestinal tract, more precisely all the wall layers of the intestine, both in the large intestine and in the Small intestine can occur. It can also be used to Formation of ulcers, Bottlenecks inside the intestine and so-called Fistulas (Connecting corridors with other organs). Typical for Crohn's disease are on the one hand the so-called. segmental infestation patternsi.e. that diseased intestinal sections alternate with healthy ones and that occur in bursts. So people who suffer from Crohn's disease can symptom-free for a long time be.
How exactly Illness arisesis also today not yet finally clarified. However, it is believed that several factors like one genetic predisposition, bad Eating habits and a Inflammatory response, in which the body makes antibodies against cells in the intestine, are involved. A disease of Crohn's disease is apparently favored by To smoke cigarettes and taking the pill.
In Crohn's disease patients, the disease usually manifests itself through unspecific symptoms how Weight loss, fatigue, Pain in the right lower abdomen and (mostly bloodless) Diarrhea. Furthermore will Anal fissures or Ulcers and aphthae in the oral cavity described. As things stand today, Crohn's disease is incurable. Therapy consists of Relieving attacks and their frequency, through the administration of drugs that immune system dampen.

Another serious bowel disease is the so-called. Ulcerative colitis, a chronic inflammatory bowel disease that also in batches occurs. It spreads continuously from the anus towards the oral cavity off, whereby there is a so-called Ulceration, i.e. defects in the intestinal mucosa. Usually ulcerative colitis occurs between the ages of 20 and 40 on.
The mechanism that triggers the disease is similar to that of Crohn's disease, not finally clarified and probably also a mixture of components such as genetic makeup, infection, and diet. The intestinal disease ulcerative colitis usually manifests itself through bloody slimy diarrheawhich can also occur at night. These go together with so-called. Tenesmen along with what one is painful need to stool or urinate understands. Some of those affected complain. also about Weight loss, fever and sometimes severe abdominal pain.
The ulcerative colitis is due to a complete surgical removal of the colon curable.

Among the diseases of the colon is also the so-called. Irritable bowel syndrome frequently. Irritable bowel syndrome is one Disease not clearly defined of the intestine, which is put in patients who are over different abdominal discomfort complain and in which other organic diseases of the gastrointestinal tract have already been excluded. Irritable bowel syndrome is not uncommon psychosomatic illnesses assigned. Women are about affected twice as often like men. Since the complaints are very different and the causes are usually difficult to identify, the therapy varies considerable.

Another inflammatory colon disease is the so-called Pseudomembranous colitisthat sometimes also on the actually poor in bacteria Skip the small intestine can. This suffering usually follows one prolonged antibiotic therapy. This also includes parts of the naturally occurring intestinal bacteria killed, so that especially the Intestinal germs multiply unhindered that are resistant to the antibiotics you are taking. Especially Bacteria of the species Clostridium difficile multiply here increasingly. They produce toxins in large quantities Trigger inflammatory reactions. In the course of this disease, a A substance called fibrin apart, which when looking at im Under a colonoscopy appears like a coating (a membrane), however strippable is (hence the prefix 'pseudo'). The therapy of choice is this Administration of antibioticsthat can kill said strains of bacteria.

The colon meridian

The colon meridian has 20 points.

Observations on the Colon meridian. In traditional Chinese medicine, the meridian is one Channel of the human body, through which the life energy flows, whereby each meridian can be assigned to an organ system. The are on these meridians Acupointsthat at Acupuncture with needles, at Acupressure by applying pressure treated with the finger. It has to be mentioned that it is neither for the existence of meridians nor for the broad effectiveness of acupuncture or acupuncture sound scientific evidence gives.

The colon meridian points 20 acupuncture points on. It runs from the index finger over the outside of the arm up to the side wing of the nose. However, puncturing or pressing points on the colon meridian helps in no way only against complaints of the colon, so the puncture can be the place where the bone of the index finger and thumb (which is considered to be the most important anti-pain point) allegedly also alleviate discomfort fever and Epistaxis impact. It is also said to have an anti-inflammatory effect.

With regard to the colon meridian, healers take following the ideas of the Traditional Chinese Medicine treat that the large intestine is also heavily involved in the Human emotion formation is involved. (There are recent gains in knowledge in pharmacology, which allow such a conclusion.) You speak to him in the sense of an interaction between the so-called Abdominal brain (see also enteric Nervous system) and Head brain admitted that he i.a. at the coping with the past contributes. After this performance it appears for example plausiblethat someone who is struggling to find his Letting go of the past, also finds it difficult Letting go of the chair (in the sense of leaving). In traditional Chinese medicine, for example, the constipation.


In an adult, the total length is approx. 150 cm. The ascending part of the colon follows the appendix (Ascending colon), followed by the transverse branch of the colon (Transverse colon, Transverse colon). It then continues with the descending part of the colon (Descending colon), which then moves into the S-shaped part of the large intestine, the Sigma (Sigmoid colon), opens. The last section of the digestive tract then lies in the small pelvis Mast- or rectum (rectum), which serves as a reservoir for the intestinal contents and through the Anal sphincter (Anal sphincter) is sealed to the outside.

According to the ideas of traditional Chinese medicine (TCM) there are 12 different "channels" or channels on the body surface through which the life energy "Qi" flows. Each of these meridians is assigned to an organ area. The body can be stimulated to heal through targeted stimulation of the points on it, either with fine needles in acupuncture or finger pressure in acupressure.
The meridian of the colon begins at the Tip of the index finger and runs towards the thumb (lat .: radial) towards the outside of the elbow. From there it pulls over the upper arm to the highest point of the shoulder to the 7th cervical vertebra. Now the large intestine meridian runs into the clavicle, from there to the lungs and finally into the large intestine itself. There is also a line connecting the clavicle, the neck and the cheek. From there it goes around the upper lip and pulls to the opposite side.