Anatomy Of The Colon And Rectum


Anatomy Of The Colon And Rectum

The human digestive system is made up of a small intestinal tract and a large intestine. The rectum and the colon are both parts of the large intestine. We will discuss how the colon works as well as the rectum. It is necessary to take consultation from the best Fistula Doctor in Kolkata.

Anatomy and Physiology

The colon is the longest section in the large intestine. It is a long, tube-like organ that drains water from the food that has been digested. It is also divided in:

The ascending colon is the place where the large intestine, into which the small intestine is empty. it starts on the lower left side of the abdomen. It goes up towards the transverse colon. It’s 20cm long.

The transverse colon extends across the abdomen’s top from left to right which leads to the lower colon, which eliminates waste from onto the right side. It is the biggest and most mobile part of the colon, measuring around 45 cm in length.

Descending colon follows the traverse colon and is located on the left in the abdominal area. It’s about 30 cm long.

In the end, the sigmoid colon is the end of the colon, which takes the waste away for a few more inches down towards the rectum. It’s 40cm long. A cross-sectional view of the sigmoid colon and rectum will show the place where waste exits the body by the system of the anus.

The transverse colon and ascending colon are referred to as colon proximal, whereas the colon descends and the sigmoid colon is known as the distal colon.

Its length is approximately 15cm. It connects the sigmoid colon to the canal of the anal. The colon is a storage facility for waste until it is released from the anus.

The colon is divided into layers and the rectum

It is composed of layers of tissue that form the colon and the rectum. They include:


The lining that surrounds both the rectum and colon is called the mucosa. It is composed of:

A thin layer of epithelial cells referred to as epithelium

connective tissue layer

Muscle layer is known as the mucosa of the muscular


The submucosa is the layer of connective tissue that surrounds the mucosa. It is home to mucous glands, lymph vessels, blood vessels, and nerves.

Muscularis propria

The muscularis propria is located in the submucosa. It is an extensive skin of muscle. 


The outermost portion of the colon is known as the serosa, which is absent in the majority of the rectum.

Functions of the colon as well as the functions of the rectum and colon

The colon and rectum

We absorb water and some of the nutrition from food and drink

design and stool for storage

Get rid of waste in the body

After digestion, food particles move through the colon via the small intestine. The colon’s tissues contract and relax, allowing food particles to move through the rectum and colon. This is known as peristalsis.

Within the colon, the bacteria break down food particles into smaller pieces. The mucosa’s outer layer mucosa sucks up water and other nutrients.

The remaining liquid waste is from the semi-solid stool. Mucosa also produces mucus, which helps stool easily move through the rectum and colon. When stool travels through the colon it absorbs more water and then becomes more solid.

After the colon is empty The stool is then moved into the rectum. The rectum houses the space to hold the stool. When the rectum is fully filled it will throw the stool away from the body through the anus.

How can you keep the health of the colon and the rectum?

Most colon and rectal issues result from poor stool movement. Sometimes, they’re too rigid or too loose. A bowel movement that is too hard can cause cuts or tears in the region of the anal and loose bowel movements can be a nuisance around the anal area and cause itching around the opening of the anal. So, if the volume and frequency of the bowel movements is adequate, then constipation and rectum issues will go away. A balanced food plan, simple elimination, and proper cleansing can help prevent issues with the colon and rectum.

Rectal and Colon Diseases And Conditions

There are a variety of issues that affect the colon and rectum that could be either structural or functional.

Functional Disorders

A condition in which there isn’t any physical injury to the rectum or the colon however the bowel fails to perform as it should. The majority of the time, people do not understand the cause.


Constipation is a frequent and painful stool movement. The stool gets hard when there isn’t a bowel movement for longer than three to four days. The reason for constipation could be an inadequate diet of fiber and fluid or water levels in the body or holding onto calls to the bathroom.

Constipation can cause strain in bowel movements and can cause anal issues like piles, fissures or fistula. It is possible to try homemade remedies for constipation. They’re very efficient.

Irritable Bowel Syndrome (IBS)

IBS is a frequent disease that affects the large colon. The colony’s muscles are contracted in an abnormal way, causing a variety of difficulties. The colon is under pressure. the colon. These contractions can cause stomach acidity, bloating and abdominal pain, or cramps. Changes in diet can help improve the symptoms of irritable colon syndrome.

Structural Disorder

If there’s a problem like soreness or cut or anything that requires to be fixed or removed for example, a section of the colon to treat diverticulitis or colon cancer.

Anal Problems

Piles or Hemorrhoids

The hemorrhoids, also known as piles, cause swelling or inflammation in the veins of the lower rectum, or the anus. There are generally two types of hemorrhoids, external and internal.

The internal hemorrhoids are blood vessels that are located inside the opening in the anterior. Internal hemorrhoids can be the result of straining too much or pressure in pregnancy. They may become inflamed, and cause bleeding, and they may also expand out of the anal opening.

Hemorrhoids are external occur just under the skin, outside of the anus. They don’t trigger any symptoms. They can be extremely painful, and they could be a concern in everyday living, especially during stool movements or sitting for long periods of time.

Methods to treat piles

Home remedies for pimples can help during the beginning stage. In the event that piles aren’t treated, they require surgical intervention. Laser treatment for piles is among the most effective treatment options that is not invasive. Find out more about piles laser therapy and get in touch with our medical coordinators should you have any questions.

Anal Fissure

Anal fissure refers to the tear in the opening of the anal that occurs as a result of constipation(hard stool) or diarrhea. The patient experiences severe pain, burning, and soreness of the anal region. Anal fissures are often misinterpreted as piles if it is diagnosed.

Treatment for Fissure:

Fissures can be treated with surgery occasionally. However, in certain instances, the laser procedure is recommended when the tear is not able to heal using medication or at-home solutions.


Perineal abscess refers to an accumulation of pus that is due to blockage or infection in the anal area. The remedy for abscesses is to drain the pus.

Anal Fistula

An anal fistula can be described as a tube connecting an infected or asymptomatic gland or abscess within the anus to an opening that surrounds the region of the anus. 

Treatment for Anal Fistula:

Laser surgery is usually recommended by Fistula Specialist Doctor in Kolkata to treat anal fistula based on the severity of the condition. Laser surgery is among the most effective treatments for anal Fistula.

Other anal infections

An abscess develops, which is filled with pus within the cleft. It is composed of hair, waste, and dirt. It may cause pain that is severe and could lead to infections. It is usually required surgery to treat.

We offer laser treatment for anorectal problems using the use of lasers that are minimally invasive.

Colon and rectal issues

Rectal Prolapse

Rectal prolapse is a condition that occurs when the Rectal Prolapse can be described as a situation where the rectum shrinks and then comes out of its anal.


It is a small bulge within the lining of the large intestine, which is usually within the colon. The bulges can trigger extreme abdominal discomfort, nausea, or a change in the frequency of bowel movements. The complications, if the problem isn’t treated promptly, could be a blockage within your colon, an abscess, or peritonitis that can be an emergency medical situation.


It is a set of disorders that can cause swelling and inflammation in the large intestine, specifically the colon and rectum. There are several types of colitis:

Infectious colitis is a condition that can be attributed to an infection within the large bowel

Ischemic colitis occurs when there is a lack of circulation of blood to the colon.

Radiation colitis (after radiation therapy, typically for rectal, prostate, or Gynecological cancer)

Ulcerative colitis

Crohn’s disease

Polyps and cancer

Colon cancer is a serious concern. The tissues that line the large intestine’s lining expand and split in an uncontrollable way. Polyps are the enlargement of abnormal colon tissues or the rectum.

Take Away

There are serious issues that require a general doctor or proctologist to determine the proper diagnosis. We know that issues with the rectum and colon cause people to feel uncomfortable to discuss. Talking to a physician is the best method to avoid them. Treatment is contingent on how severe the problem is and the appropriate treatment for the patient. The issue could be a result of fistula, piles, fissure or abscess, fecal incontinence, or prolapse.

So, timely medical treatment will help prevent colon and rectum illnesses. Rectal exams are recommended prior to beginning any treatment. Know more about it.

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