Difference Between Colitis and Diverticulitis (With Table)

The difference between colitis and diverticulitis can be hard to distinguish as both cause similar abdominal pain. Colitis and diverticulitis are inflammatory diseases that can affect the colon and rectum in our large intestine. Though both the diseases show some similar symptoms, colitis causes inflammation of the colon whereas diverticulitis causes inflammation of the diverticula. 

Colitis vs Diverticulitis

The difference between colitis and diverticulitis is that colitis causes inflammation of the colon whereas diverticulitis is a diverticular disease that causes inflammation to the diverticula in the colon. When a person gets colitis, the formation of ulcers (ulcerative colitis) takes place in the small intestine and diverticulitis takes place when the bulges on the lining of the colon called diverticula get infected. 

Colitis causes inflammation of the colon and the formation of ulcers in the digestive tract. The symptoms of colitis grow over time and not suddenly. If not treated quickly, patients with colitis may suffer life-threatening consequences. The common symptoms of colitis are diarrhea, blood or pus in the stool, and abdominal pain. 

Diverticula refers to the formation of small bulging pouches especially in the lower part of the large intestine. The inflammation of these outward bulging pouches is called diverticulitis and it mostly occurs in people who are past 40. If diverticulitis is diagnosed in an early stage, antibiotics and medications can cure it but severe cases require surgery. 

Comparison Table Between Colitis and Diverticulitis

Parameters of ComparisonColitisDiverticulitis
Type of diseaseColitis accompanies inflammation and the formation of ulcers in the colon. Diverticulitis causes inflammation in the diverticula which are small bulging pouches in the large intestine. 
SymptomsDiarrhea along with blood in the stool, abdominal cramps, irregular bowels, fatigue, fever, and weight loss. Extreme abdominal pain and crampings, nausea and vomiting, constipation, and diarrhea (not a very common symptom).
CausesFormation of bacteria in the digestive system due to environmental factors. Lack of dietary fiber causes constipation which causes the formation of the diverticula. Obesity is also one of the causes. 
DiagnosisA colonoscopy with biopsy is a common form of diagnosis for all types of colitis. Colonoscopy, sigmoidoscopy, barium enema are some of the common tests. 
TreatmentChange in lifestyle and medications like corticosteroids, biologics, and immunosuppressants. Most cases of diverticulitis are cured by prescribing antibiotics. 

What is Colitis?

Colitis is an inflammatory disease that refers to the inflammation of the inner lining of the colon. Bacterial infection and inflammatory bowel disease (IBD) are the two most common causes of colitis. Among the IBD, Crohn’s disease and ulcerative colitis are very common. 

The most common symptoms of colitis are abdominal pain and cramping, diarrhea, and blood in the stool. Other symptoms of the disease may vary with the cause and may include fever, fatigue, canker sores, joint swelling, dehydration, etc. The patient should immediately consult a doctor in the case of blood or pus in the stool. 

Many bacterias are responsible for causing colitis in our colon. Some of them are E. Coli, Salmonella, and Shigella. Bacterias invade our small and large intestines when the patient consumes contaminated food. For example, drinking infected water due to unhygienic circumstances results in the growth of parasite infection of Entamoeba histolytica in our colon. This further causes colitis.

Different bacterias and other factors are responsible for causing colitis. A person has a higher risk of colitis if his/her parents or siblings have it. Colitis can lead to severe bleeding and rapid swelling of the colon. So, a doctor should be consulted immediately as the symptoms start showing up. 

What is Diverticulitis?

Diverticulitis is a disease that can affect a single or more diverticulum. It is the inflammation of the diverticulum (plural of diverticula) when a bacteria causes infection. In the modern world, diverticulitis is very common and a person can have it at any stage of their lifetime. The presence of diverticula means diverticulosis and it is not the same as having the disease diverticulitis. 

Though some scientists believe that constipation causes diverticulitis, recent studies show that people with obesity and high body mass index are also most likely to suffer from diverticulitis. It is important to change lifestyle and cut junk food in general to reduce chances of catching such disease. 

The most common symptoms of the disease include lower abdominal pain, an increase in abdominal size, irregular bowel movements (constipation is common), etc. If these symptoms arrive, do not panic and visit a doctor for a checkup. Diverticulitis is a less fatal disease than colitis and can be treated with proper medication. 

To correctly diagnose diverticulitis, colonoscopy or sigmoidoscopy are the most common tests. Before going for either of the tests, emptying bowels is a must requirement. 

Main Differences Between Colitis and Diverticulitis

  1. Colitis is the formation of ulcers (sores) in the colon whereas diverticulitis is the infection of diverticula which mostly forms in people above 40 years.
  2. The main symptoms of colitis are abdominal pain, diarrhea, and blood and mucus in the stool. On the other hand, diverticulitis causes constipation and extreme abdominal cramps. Diarrhea is a less common symptom of diverticulitis. 
  3. The exact cause behind the cause of colitis is not known but most experts say that it happens due to a combination of genetics and environment. It leads to the formation of bacteria in the digestive tract. Lack of dietary fiber causes constipation and leads to the formation of diverticula. Bacteria in our stool infects the diverticula causing diverticulitis. 
  4. Colonoscopy and biopsy can confirm colitis whereas diverticulitis is confirmed by colonoscopy, sigmoidoscopy, barium enema, and checking of the stool sample. 
  5. In some severe cases of colitis, surgery is required whereas diverticulitis is a less severe disease than colitis and it is mostly cured at home by taking pescribed antibiotics. 


Colitis is the inflammation of the inner lining of the colon whereas diverticulitis takes place due to infected diverticula. Several types of bacteria are responsible for both diseases. But, lack of dietary fiber in the first place is the reason behind the formation of diverticula in the lower part of the large intestine.

Diverticulitis is a less severe disease than colitis, but it is recommended to visit a doctor immediately if symptoms of either of the disease are noticed.  In most cases of both the disease, change in lifestyle and food diet and taking proper drugs cures it. But, in extreme cases of colitis, surgery can be performed. 


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1981500/
  2. https://www.nejm.org/doi/full/10.1056/nejmcp073228

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