Swollen colon: Causes and symptoms

swollen colonA swollen colon is a manifestation of chronic inflammatory conditions that affect the intestines and is thought to be caused by the body’s own immune system. Normally, the immune system is supposed to act as the first line of defense against bacteria and other foreign invaders to protect the body, but in an unknown twist, it instead attacks itself. In the case of inflammatory bowel conditions, it leads to swelling of intestinal tissue.

Disorders such as ulcerative colitis and Crohn’s disease are the most common examples of an inflammatory bowel condition and are thought to be attributed to an autoimmune reaction. Those affected often suffer from episodic symptoms such as abdominal pain and diarrhea, with researchers still attempting to find the precise cause of their occurrence.


Recent studies have uncovered some of the mystery behind these inflammatory conditions, with the involvement of a particular protein linked to their development called Bcl-3.

“With the help of our cooperation partners, we were able to demonstrate that the level of the Bcl-3 protein, which also plays a role in the development of various cancerous diseases, is elevated in the intestinal tract of colitis patients and is indeed a trigger of the disease,” said Dr. Nadine Hövelmeyer, head of the work group at the Mainz-based Institute for Molecular Medicine. 

This protein was found to suppress the actions of regulatory T-cells (Tregs), which are responsible for preventing the over-reaction of the immune system. This results in the immune system to no longer be regulated, leading to the development of inflammatory bowel disorders, according to the researchers.

Further research is being conducted to search for new active agents that will prevent this process from occurring.

What are the causes of swollen colon?

A swollen colon can have a variety of causes with your doctor having to do a multitude of different tests to help pinpoint the reasons for its development. Infections, blood flow problems, and immune system problems are all potential causes for a swollen colon. Direct contact with chemicals, such as during an enema, may also cause the condition.

The primary process for symptom development is due to inflammation. When the tissue layers of the colon become inflamed, it produces the symptoms commonly attributed to inflammatory bowel conditions.

Swollen colon on left and right side

The side that the inflammatory reactions occur can determine the diagnosis and potential treatments for that particular condition.

Swollen colon on the left side

A swollen colon on the left side, also called the descending colon, may be caused by the following:

  • Infection: Viruses, bacteria, and parasites are common causes of a swollen colon. Infection can lead to bloody or non-bloody diarrhea and dehydration. If not treated in a prompt manner, excessive levels of dehydration can lead to serious consequences and even death.
  • Blood flow problems: A condition called ischemic colic is where the arteries of the colon become narrowed or compromised, resulting in decreased blood flow. Proper blood supply is required by the entire intestinal tract for normal functioning as well as to keep tissues alive and healthy. Examples of blood flow problems may occur from a condition called volvulus, whereby the colon becomes twisted on itself, resulting in vessel strangulation. Incarcerated hernia is another condition where the outpouching of intestinal tissue leads to poor blood flow.
  • Ulcerative colitis or Crohn’s disease: Both are considered inflammatory bowel diseases and are believed to be autoimmune in nature. Both have similar symptoms of abdominal pain, spasms, and cramping, but affect different parts of the intestinal tract and are treated in different manners. These conditions can be controlled with dietary changes and the use of over-the-counter or prescription medication, but there is no cure as of yet for either.
  • Collagenous colitis or lymphocytic colitis: Relatively rare conditions that occur among older women.
  • Presences of chemical substances: Enemas are procedures that inject liquid or gas into the rectum, typically designed to help expel its contents in cases of constipation or as a cleanse. However, some of these procedures may utilize harmful chemicals that could result in swelling of the colon upon repeated use. It is therefore recommended to have a doctor treat your case of severe constipation.

Swollen colon on the right side

Also known as the ascending colon, pathology on the right side can be caused by the following:

  • Infections
  • Inflammation
  • Trauma
  • Growths or tumors
  • Vascular issues
  • Obstructions

Symptoms of swollen colon

Bothersome symptoms are often what prompt patients to seek the advice of a medical professional. Since a swollen colon has a variety of causes, your symptoms and how they present are important clues your doctor needs in order provide an accurate diagnosis. Knowing what is causing your symptoms will help you prevent them from becoming worse and prevent possible complications.

The following are symptoms commonly attributed to a swollen colon:

  • Diarrhea: Can occur as either soft or watery stool. This is the most common symptom of inflammation of the colon. The colon is typically involved in absorbing water and forming stool. If this becomes compromised by inflammation, the colon’s ability to achieve this becomes difficult. Infections resulting in the imbalance of intestinal bacteria is a common cause of intestinal inflammation and diarrhea production.Interestingly, if the inflamed region of the intestine happens to affect only the very last part of the colon, most of the water will have already been absorbed, leading to minimal or absent diarrhea.
  • Abdominal pain: This typically manifests as cramping pain occurring in intermittent spasms. Bowel inflammation stimulates contractions of the intestinal walls causing pain. Also, the location of the pain may be a clue to which side of the bowel is affected.
  • Other associated symptoms:
      o Bloating: a common occurrence due to increased volume of stool in the colon
      o Bleeding: often seen mixed with stool and a result of tissue damage to the lining of the colon.
      o Anemia: a possible result of excess bleeding
      o Mucus in stool: a feature of ulcerative colitis
      o Tenesmus: the urge to have a bowel movement
      o High fever
      o Weight loss
      o Fatigue



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Author Bio

Devon Andre has been involved in the health and dietary supplement industry for a number of years. Devon has written extensively for Bel Marra Health. He has a Bachelor of Forensic Science from the University of Windsor, and went on to complete a Juris Doctor from the University of Pittsburgh. Devon is keenly aware of trends and new developments in the area of health and wellness. He embraces an active lifestyle combining diet, exercise and healthy choices. By working to inform readers of the options available to them, he hopes to improve their health and quality of life.



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