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Difference between diverticulitis and colitis: Diverticulitis vs. Ulcerative Colitis (UC): Differences & Symptoms


Difference Between Colitis and Diverticulitis

Key Difference – Colitis vs Diverticulitis

Colitis and diverticulitis are two inflammatory diseases of the colon that are difficult to be diagnosed solely based on the clinical features. The inflammation of the colon is known as colitis. Diverticulitis is the inflammation of the diverticula in the colon. As seen from the definitions, colitis is a condition that occurs in the colon whereas diverticulitis is a condition that takes place in the diverticula. This is the main difference between colitis and diverticulitis.


1. Overview and Key Difference
2. What is Colitis
3. What is Diverticulitis
4. Similarities Between Colitis and Diverticulitis
5. Side by Side Comparison – Colitis vs Diverticulitis in Tabular Form
6. Summary

What is Colitis?

The inflammation of the colon is known as colitis. Clinical features of this condition vary according to the underlying pathology.

Main Causes

Crohn’s Disease

Crohn’s disease is an inflammatory bowel disease characterized by the transmural inflammation of the colonic mucosa. Usually, only some regions of the colon are inflamed, giving rise to skip lesions rather than a continuous involvement.

Clinical Picture


Diarrhea in Crohn’s disease is due to the excessive secretion of the fluids and the impaired absorption of fluids by the inflamed bowel mucosa. In addition, the malabsorption of bile salts by the inflamed terminal ileum also contributes to the aggravation of diarrhea.

Fibrostenotic Disease

The obstruction of the gastrointestinal tract due to small bowel strictures or colonic strictures can give rise to symptoms such as abdominal pain, constipation, nausea, and vomiting.

Fistulizing Disease

The transmural inflammation of the GIT can be the cause of sinus tracts, serosal penetration, and fistulae such as enteroenteric fistulae. The penetration of the bowel by the inflammatory lesions leads to the leakage of colonic substances into the peritoneal cavity, resulting in peritonitis and other associated complications.

Local complications of Crohn’s disease
  • Watery diarrhea due to the stimulatory effects on colonic water and electrolyte absorption
  • The reduced concentration of bile acids interrupts the absorption of fat thus resulting in steatorrhea
  • Long-term steatorrhea can lead to osteoporosis, malnutrition and clotting abnormalities
  • Formation of gallstones
  • Nephrolithiasis (formation of kidney stones)
  • Vitamin B12 malabsorption

Crohn’s disease increases the risk of colon cancers, lymphomas and squamous cell carcinomas of the anus.


Mostly the right side of the colon is affected by the Crohn’s disease. There is a segmental distribution of the lesions. Usually, the rectum is spared.

There is a transmural involvement with the occurrence of fissures and noncaseating granulomas.


The clinical history and examination play a vital role in the diagnosis of CD.

Endoscopy reveals the presence of the presence of aphthous ulcers that give rise to a cobblestone appearance. Abdominal and pelvic scanning can be used to identify any abscesses.


There is no definite cure for the Crohn’s disease. The aim of treatment is the suppression of inflammatory processes that give rise to the clinically manifested signs and symptoms.

  • Anti-inflammatory drugs – Corticosteroids such as prednisolone and Aminosalicylates
  • Immune system suppressors such as azathioprine and biological agents such as infliximab
  • Antibiotics
  • Analgesics
  • Antidiarrheals
  • Iron and vitamin B12 supplements

In some cases, surgical removal of the damaged parts of the colon is required.

Ulcerative Colitis

Ulcerative colitis is an inflammatory disease of the rectum extending proximally to variable distance. Women are more likely to be affected by this condition than men.

Clinical Features
  • Blood and mucus diarrhea
  • Cramp-like abdominal pain
  • Per rectal bleeding
  • In some cases, there can be toxemia, fever and severe bleeding.
  • Sigmoidoscopy
  • Colonoscopy
  • Barium enema
  • Examination of the stools reveals the presence of blood and pus

    Figure 01: Histopathological image of the active stage of ulcerative colitis

Local complications
  • Toxic dilatation
  • Hemorrhage
  • Stricture
  • Malignant changes
  • Perianal diseases such as anal fissures and anal fistulae.
General Complications
  • Toxemia
  • Anemia
  • Weight loss
  • Arthritis and uveitis
  • Dermatological manifestations such as pyoderma gangrenosum
  • Primary sclerosing cholangitis


Medical Management

A high protein diet with vitamin supplements and iron is prescribed. Blood transfusion may be required if the patient shows clinical signs of severe anemia. Loperamide is usually given to control diarrhea. The administration of corticosteroids as per rectal infusions induces remission in an acute attack. Immunosuppressors such as infliximab are required to control more severe attacks of ulcerative colitis.

Surgical Management

Surgical intervention is indicated only in the following situations.

  • Fulminating disease not responding to medical treatments
  • Chronic disease not responding to medical treatments
  • Prophylaxis against malignant changes
  • In the occasions where the patient presents with the complications mentioned above.

What is Diverticulitis?

Diverticulitis is the inflammation of the diverticula in the colon. These diverticula can be of either congenital or acquired origin.

An inflamed diverticulum can give rise to the following complications.

  • The diverticulum can perforate into the peritoneum resulting in peritonitis. Pericolic abscesses can be formed if it penetrates the pericolic tissues. Its perforation into any other adjacent structure is most likely to end up with the occurrence of fistula.
  • The chronic inflammation associated with diverticulitis leads to fibrosis of the inflamed tissues giving rise to obstructive symptoms such as constipation.
  • The erosion into blood vessels results in internal hemorrhages.

Clinical Features

Acute Diverticulitis

This condition is known as the left-sided appendicitis because of the characteristic pain of acute onset that originates in the low central region of the abdomen and gradually shifts to the left iliac fossa. There can be other nonspecific symptoms such as nausea, vomiting, and local tenderness.

Chronic Diverticular Disease

This mimics the clinical features of a colonic carcinoma.

  • Change in bowel habits
  • Vomiting, abdominal bloating, colicky abdominal pain, and constipation due to the obstruction of the large bowel.
  • Blood and mucus per rectum


  • CT is the most appropriate investigation to identify diverticulitis in its acute stage by excluding other possible diagnoses.
  • Sigmoidoscopy
  • Colonoscopy
  • Barium enema

Figure 02: Intraoperative view of sigma diverticulum


Acute Diverticulitis:

Conservative management is recommended for treating a patient diagnosed with acute diverticulitis. The patient is kept on a fluid diet and antibiotics such as metronidazole and ciprofloxacin.

  • Pericolic abscesses are diagnosed by CT. Percutaneous drainage of these abscesses is essential to avoid any future complications.
  • In case of a ruptured abscess giving rise to peritonitis, the pus should be removed from the peritoneal cavity by laparoscopic lavage and drainage.
  • When there is a diverticulitis associated obstruction in the colon, laparotomy is required to establish the diagnosis.
Chronic Diverticular Disease

This condition is managed conservatively if the symptoms are mild and the diagnosis has been confirmed through investigations. Usually, a lubricant laxative and high fiber containing diet are prescribed. When the symptoms are severe, and the possibility of a colonic carcinoma cannot be excluded, laparotomy and resection of the sigmoid colon are carried out.

What are the Similarities Between Colitis and Diverticulitis?

  • Both are inflammatory processes.
  • Abdominal pain is observed as a clinical symptom in both conditions.

What is the Difference Between Colitis and Diverticulitis?

Colitis vs Diverticulitis

The inflammation of the colon is known as colitis. The inflammation of the diverticula in the colon is known as diverticulitis.
This occurs in the colon. This occurs in the diverticula.

Summary – Colitis vs Diverticulitis

Diverticulitis is the inflammation of the diverticula in the colon. The inflammation of the colon is known as colitis. The main difference between colitis and diverticulitis is that they occur in two separate sites.

Download PDF Version of Colitis vs Diverticulitis

You can download PDF version of this article and use it for offline purposes as per citation note. Please download PDF version here Difference Between Colitis and Diverticulitis


1. Ellis, Harold, et al. General Surgery: Lecture notes. Chichester, Wiley, 2011.

Image Courtesy:

1.”Ulcerative colitis (2) endoscopic biopsy” By User:KGH – Own work (CC BY-SA 3.0) via Commons Wikimedia
2.”Intraoperative view of sigmoid diverticulitis” By Anpol42 – Own work (CC BY-SA 4.0) via Commons Wikimedia

Diverticulosis and Diverticulitis: What’s the Difference?

It’s easy to get the care you need.

See a Premier Physician Network provider near you.

Chances are, you don’t think much about your digestive tract — unless it’s giving you trouble.

A condition called diverticulosis, which is not uncommon for women over 50 (though men are at greater risk), can lead to trouble. With this condition, small pouches — diverticula — form in the colon (or intestinal) wall. And this can increase your risk of a painful bout of diverticulitis — an infection or inflammation of the pouches.

The good news? “Only a small number of people with diverticulosis have diverticulitis,” says Fayez Abboud, MD, gastroenterologist with Premier Gastroenterology Specialists.

Dr. Fayez Abboud talks about diverticulitis.

Click play to watch the video or read video transcript.

Diverticulitis is when some of the people with diverticulosis develop infections or an inflammation in these little sacs that protrude out. Only a small number of people with diverticulosis have diverticulitis.

The symptoms of diverticulitis are usually abdominal pain. Usually in the left, lower part of the abdomen. Pain, sometimes you can have fever, and tenderness; which means if you push on the abdomen you have pain with the pushing on it. These are the most common symptoms.

If it becomes very severe then it requires putting the patient in the hospital for treatment. The diverticulitis can become perforated, which is … Only a small number of people with diverticulitis have perforation, which is a serious condition where there’s a small little hole or a tear in one of these little sacs that leaks the contents of the bowel into the abdomen. That is a serious condition that usually requires surgery.

Diverticulitis, most cases of diverticulitis are acute. It’s a sudden attack, the patients know about it. But a small number of patients have recurrent, acute diverticulitis. They have recurrent episodes of these attacks. A small number of them can develop chronic diverticular disease, which is kind of a low grade degree of diverticulitis with some mild and chronic low grade discomfort. So it is possible for diverticulitis to become chronic to some extent.

Learn more about the link between the two, and what you can do when symptoms signal that something is wrong.

What Causes Diverticulitis and Diverticulosis?

Experts don’t know for sure what causes these conditions, but several factors may play a role:

  • High pressure in the colon: Muscle spasms in the colon or straining to have a bowel movement may cause bulges to form at weak spots.
  • Family history: The genes you inherit may make you more likely to develop diverticulosis and diverticulitis.
  • Medications: Studies have uncovered connections between these digestive conditions and some medicines, including nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin.
  • Lifestyle: Lack of exercise, obesity and smoking may also contribute.

Dr. Fayez Abboud talks about what causes diverticulitis.

Click play to watch the video or read video transcript.

What causes diverticulitis? It’s not completely clear, but it is an infection and/or inflammation in one of the pockets. It is a common misconception that people are told to avoid seeds, or that people are told to avoid seeds, nuts, popcorn. Really the studies show that there is no clear evidence that avoiding these lead to diverticulitis.

What Are the Symptoms?

Diverticulosis: Most people with diverticulosis don’t even know they have it. But if you do have symptoms, they may include:

  • Bloating
  • Constipation
    Cramping or pain in your lower abdomen

Diverticulitis: With diverticulitis, the inflamed pouches typically trigger pain in the lower left side of your abdomen. The pain is often severe and comes on suddenly. Other symptoms include:

  • Constipation or diarrhea
  • Fevers and chills
  • Nausea or vomiting

See your doctor right away if you are troubled by any of these symptoms.

With diverticulitis, the inflamed pouches typically trigger pain in the lower left side of your abdomen. The pain is often severe and comes on suddenly.

How Are Diverticulitis and Diverticulosis Diagnosed?

If your health care provider believes you have one or both conditions, based on your symptoms, she may make her diagnosis using the following:

  • Medical history: Your doctor will ask about your bowel movement frequency, diet, overall health, what medicines you take and what symptoms you are experiencing.
  • Physical exam: Your doctor will perform an exam, which may include a digital rectal exam, when she slides a gloved, lubricated finger into your anus to check for pain, bleeding, hemorrhoids or other problems.

Your doctor may also use one of these tests:

  • CT scan: This uses computer technology to combine multiple X-rays into a detailed image of your gastrointestinal (GI) tract.
  • Barium enema: A chalky, liquid solution of barium sulfate, introduced by enema, coats the large intestine to help provide clear X-ray images of your large intestine. This procedure is also called a lower GI series.
  • Colonoscopy: Using a thin, flexible tube with a tiny camera on the end, this test provides a look inside your rectum and colon.

Dr. Fayez Abboud talks about diagnosing and treating diverticulitis.

Click play to watch the video or read video transcript.

Diverticulitis is usually diagnosed by, initially, the clinical picture. People presenting with symptoms to suggest it. The examination, when we feel the abdomen and it’s tender where the diverticulosis is usually present. A CT scan of the abdomen usually confirms this diagnosis.

If somebody gets an acute diverticulitis every two or three years it can be treated with antibiotics. Having frequent attacks of diverticulitis can lead to complications, adhesions. Things stick together in the abdomen and then you can have something called “fistula,” when you develop an abnormal connection between the colon and the bladder or other organs.

How Are Diverticulitis and Diverticulosis Treated?

Diverticulosis: With the goal of preventing bothersome symptoms or more serious problems like diverticulitis, these can help:

  • High-fiber diet: Foods rich in fiber can help you avoid symptoms if you already have the condition. Increase fiber in your diet slowly to decrease the chances of abdominal gas and pain. 
  • Medicines: Mesalazine (Asacol) and the antibiotic rifaximin (Xifaxan) may help reduce symptoms.
  • Probiotics: Probiotics are healthy bacteria, like those that naturally live in your stomach and intestines. You can find them in dietary supplements and in foods like yogurt. Talk with your doctor or health care provider first about using these or any alternative medicines.

Diverticulitis: Treatment will depend on your symptoms.

  • Mild symptoms: You may be put on a liquid diet for a short time. Antibiotics are often prescribed. If these help, your doctor may put you on a high-fiber diet.
  • Severe symptoms: You may be admitted to the hospital, where you can be given intravenous (IV) antibiotics and fluids. You will also be put on a low-fiber or liquid diet. In rare cases, surgery may be needed. 

It’s easy to get the care you need.

See a Premier Physician Network provider near you.

Source: National Institutes of Health; American College of Gastroenterology; International Foundation for Functional Gastrointestinal Orders; Fayez Abboud, MD, Premier Gastroenterology Specialists

A comparison of diverticulitis in Crohn’s disease versus ulcerative colitis – Persaud – 2019 – JGH Open


Inflammatory bowel disease (IBD) and diverticulitis are both inflammatory conditions of the bowel that lead to increased morbidity and mortality in patients. In industrialized regions, diverticular disease is a relatively common condition, with a prevalence ranging from 7 to 45%, but predominantly occurs in those older than 60 years of age.1-3 Moreover, a nationwide study in the United States showed a 26% increase in hospital admissions from 1998 to 2005 due to diverticular disease.4 Diverticulosis occurs where the vasa recta enters the muscle layer of the colon, leading to mucosal herniation through areas of colonic weakness.5 Diverticulitis ensues when a diverticulum undergoes micro or macroscopic perforations, leading to inflammation, usually as a result of increased intraluminal pressures.1, 6

Crohn’s disease (CD) is characterized by transmural inflammation that can involve any part of the gastrointestinal tract.7, 8 In contrast, ulcerative colitis (UC) is characterized by mucosal layer inflammation that occurs from the rectum and can extend proximally through the colon in a contiguous manner. Perianal disease and endoscopic examination of cobble-stoning, aphthous ulcerations, and biopsies showing granulomas, usually differentiate diverticulitis from CD.8, 9 However, segmental colitis associated with diverticula (SCAD), described in the literature as inflammation in the interdiverticular mucosa without involving the orifices, has been occasionally associated with both UC and CD.10, 11

Interestingly, a prospective study showed that the prevalence of diverticular disease in UC was found to be lower than controls.12 On the other hand, CD has been associated with a higher incidence of diverticulitis than would be expected in a population with non-IBD diverticular disease.8, 13

Moreover, each of these conditions is associated with a substantial financial burden. For example, hospitalization for UC is estimated to be between $19 000 and $29 000, depending on the severity of illness,14 while treatment of CD flares typically costs closer to $25 000, contingent on the need for surgery.15 In addition, the average cost of diverticulitis hospitalization has been estimated to be around $5000.16 This study aims to evaluate whether hospitalization outcomes differ for patients with acute diverticulitis and a history of CD compared to UC.


Data source

The national in-patient sample (NIS) represents 20% of all nonfederal hospitals in the United States. This large database was queried for demographic information of the population admitted for acute diverticulitis using the International Classification of Diseases-Ninth Edition Revision-Clinical Modification (ICD-9 CM). The NIS is a product of the Agency for Healthcare Research and Quality and contains patient information that has been deidentified. This is a nationally representative subset acquired through hospital discharge records and is the largest in-patient database currently available in the United States. While a proportion of the national population has been sampled, yearly sampling weights are applied, which then provide national estimates.17 Years of data and a multitude of works have verified the value of this sampling tool, and thus, it has been utilized for this study.

Study design and inclusion criteria

This is a cross-sectional study and includes all patients ≥ 18 years old with a primary diagnosis of acute diverticulitis in 2014. The ICD-9 CM codes used were 56 211, 56 201, 56 213, and 56 203. The database was then queried to include all patients with prior diagnosis of CD (5559, 555, 5550, 5551) or UC (5569, 556, 5568, 5565, 5566). Patients included in the study were required to have a primary diagnosis of acute diverticulitis with a prior diagnosis of either UC or CD. Primary study outcomes included mortality, cost of hospitalization, and length of stay (LOS) for diverticulitis with either UC or CD. A second comparison was made between those with CD and those without IBD. Various patient demographics (age, race, gender, income, and insurance status), comorbidities, and hospital characteristics (region and size) were obtained. The severity of the co-morbidities was analyzed via the Deyo modification of the Charlson comorbidity index (CCI). This index measures 17 common medical conditions and assigns different weights to compile a score from 0 to 33, which correlates with overall severity of illness.

Statistical analysis

Stata IC version 13 (StataCorp LP, College Station, TX, USA) was used for all statistical analyses. Specifically, the svy suite of commands was the extension package that was utilized. Categorical variables were analyzed with the χ2 test, while continuous variables were analyzed with the adjusted Wald’s test. Hypothesis testing was two-sided. A multivariate logistic regression model was designed to investigate the association between acute diverticulitis and either UC or CD. The hierarchal model included both hospital-level characteristics (hospital teaching status, bed size, region) and patient-level characteristics (age, race, gender, comorbidities) and the CCI. To eliminate the effect of confounders, this was the primary means by which adjustments were made in the data for patient- and hospital-level characteristics. Univariate analysis was first conducted on all of the above factors and comorbidities that could affect diverticulitis hospitalization. Age, race, hospital location, hospital teaching status, and CCI were included in the final multivariate logistic regression model as P < 0.05, indicating statistical significance on univariate analysis. In the second comparison, between those with CD and those without IBD, age, gender, race, hospital location, hospital region, hospital size, CCI, diabetes mellitus type 2, congestive heart failure, chronic lung disease, and renal failure were included in the final multivariate logistic regression model as P < 0.05 was statistically significant on univariate analysis.

Ethical considerations

The data in the NIS are publicly available, and as a retrospective study, no patients were actively involved in the data collection process. Thus, it was not subject to Institutional Review Board approval, and informed consent was not needed.18


In this study, we examined the population of those hospitalized for acute diverticulitis with prior diagnosis of IBD. There were 1815 patients meeting inclusion criteria, and 60% had CD, as shown in Table 1. The populations were largely similar in terms of age (60 ± 1.06 years old in CD vs 65 ± 1.32 years old in UC, P = 0.0), were predominantly female (57% in CD vs 67% in UC, P = 0.08), and were primarily Caucasian (87% in CD vs 84% in UC, P = 0.70). Comparing CD to UC, comorbidities that were most prevalent include hypertension (55% vs 55%, P = 0.98), followed by chronic obstructive pulmonary disease (20.64% vs 15.86%, P = 0.25), end-stage renal disease (8.72% vs 6.21%, P = 0.38), and congestive heart failure (5.96% vs 7.59%, P = 0.54). Among the two cohorts, there were no statistically significant differences with regard to comorbidities.

Table 1.
Unadjusted baseline characteristics of diverticulitis in Crohn’s disease versus ulcerative colitis

Variable Crohn’s disease (n = 1090) Ulcerative colitis (n = 725) P value
Age (SEM) 59.59 (1.06) 65.3 (1.32) 0
Female (%) 8251 (57) 486 (67) 0.08
Race 0.7
Caucasian (%) 943 (86.5) 607 (83.7)
Black (%) 65 (5.97) 20 (2.76)
Hispanic (%) 60 (5.47) 57 (7.86)
Asian (%) 6 (0.5) 41 (5.66)
Other (%) 16 (1.5) 0%
COPD (%) 225 (20.64) 109 (15.86) 0.25
ESRD (%) 95 (8.72) 45 (6.21) 0.38
CHF (%) 65 (5.96) 55 (7.59) 0.54
Liver Disease (%) 55 (5.05) 10 (1.38) 0.07
DMcx (%) 25 (2.29) 10 (1.38) 0.53
HTN (%) 600 (55.05) 400 (55.17) 0.98
CCI (%) 0.88
0 652 (59.82) 405 (55.86)
1 198 (18.8) 160 (22.07)
2 135 (12.4) 85 (11.72)
3 105 (9.63) 75 (10.34)
Hospital size 0.3
Small (%) 61 (5.56) 58 (8.01)
Medium (%) 61 (5.56) 139 (19.20)
Large (%) 968 (88.9) 528 (72.8)
Hospital region 0.71
Northeast (%) 225 (20.64) 175 (24.14)
Midwest (%) 250 (22.94) 165 (22.76)
South (%) 460 (42.2) 265 (36.55)
West (%) 155 (14.22) 120 (16.55)
Insurance 0.06
Northeast (%) 473 (43.4) 373 (51.45)
Midwest (%) 93 (8.49) 68 (9.42)
South (%) 427 (39.15) 266 (36.70)
West (%) 97 (8.90) 18 (2.48)
Income 0.3
Medicare (%) 253 (23.20) 153 (21.13)
Medicaid (%) 289 (26.51) 255 (35.20)
Private insurance (%) 310 (28.44) 158 (21.83)
Self-pay (%) 238 (21.8) 159 (21.93)
  • Values are % except for age (mean + standard error mean).
  • CCI, Charlson comorbidity index; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; DMcx, complicated diabetes mellitus type 2; ESRD, end-stage renal disease; HTN, hypertension.

However, hospital measures showed that UC incurred a much heavier hospitalization burden, as seen in Table 2. LOS in the UC cohort was markedly increased compared to the CD cohort (6.4 ± 0.53 days vs 4.7 ± 0.24 days, P = < 0.00), while the cost of hospitalization proportionally rose in the UC cohort compared to the CD cohort ($51 923 ± $6615 vs $36 140 ± $2245, P = 0.02). There were also 20 colectomies documented in the UC cohort, while none were documented in the CD cohort. Age, race, hospital location, hospital teaching status, and CCI were included in the logistic regression model, which confirmed that CD was associated with a decrease in the cost (OR −15 783, 95% CI −29 475 to −2091, P = 0.02; aOR −14 537, 95% CI −27 316 to −1758, P = 0.03) and LOS (OR −1.70, 95% CI −2.85 to −0.55, P = 0.37; aOR −1.31, 95% CI −2.41 to −0.21, P = 0.02) of hospitalization (Table 3). Moreover, there was an observed difference in mortality comparing CD to UC (OR 0.44, 95% CI 0.07 to 2.66, P = 0.37; aOR 0.90, 95% CI 0.10 to 7.87, P = 0.92), although this was not statistically significant.

Table 2.
Hospital outcome measures

Outcome Ulcerative colitis Crohn’s disease No IBD P value (CD vs UC) P value (CD vs No IBD)
Died (%) 15 (2.1) 10 (0.9) 914 (0.42)
Mean LOS (SEM) 6.4 (0.53) 4.73 (0.24) 4.70 (0.03) <0.00 0.9
Cost of hospitalization (SEM) $51 923 ($6615) $36 140 ($2245) $38 793 ($442) 0.02 0.28
Colectomy (%) 20 (2.8) 0 985 (0.45)
  • Mean reported ± SEM.
  • CD, Crohn’s disease; IBD, inflammatory bowel disease; LOS, length of stay; UC, ulcerative colitis.

Table 3.
Effect of Crohn’s disease versus ulcerative on diverticulitis hospitalization

Unadjusted odds ratio 95% CI P value Adjusted odds ratio 95% CI P value
Died 0.44 0.07 to 2.66 0.37 0.90 0.102 to 7.87 0.92
Length of stay (days) −1.70 −2.85 to −0.55 <0.00 −1.31 −2.41 to −0.21 0.02
Cost of hospitalization −15 783 −29 475 to −2091 0.02 −14 537 −27 316 to −1758 0.03

An additional analysis was conducted with acute diverticulitis but comparing CD to the population without IBD. There were 219 815 patients in this cohort, with a median age of 60 ± 1.06 years in CD versus 60.4 ± 0.09 years without IBD (P = 0.41), with Caucasian prevalence (87% in CD vs 77% without IBD, P = 0.70) and slight female predominance (57% in CD vs 58% without IBD, P = 0.73). As in the previous cohort, the most common comorbidities are hypertension (55% in CD vs 54% without IBD, P = 0.67), chronic obstructive pulmonary disease (21% in CD vs 16% without IBD, P = 0.09), and end-stage renal disease (8.7% in CD vs 7% without IBD, P = 0.31) (Table 4). In terms of hospital measures, there was an interesting contrast to the prior set of hospital outcomes. Comparing the population with CD to those without IBD, there was negligible difference between the mortality rates (0.9% vs 0.42%), and both the hospital LOS (4.73 ± 0.24 days vs 4.70 ± 0.03 days, P = 0.90) and the cost of hospitalization ($36 140 ± $2245 vs $38 793 ± $442, P = 0.28) were nearly identical (Table 2). Between the cohort with CD and those without IBD, multivariate logistic regression also reflected these findings, showing no difference in mortality (OR 2.22, 95% CI 0.55 to 9.05, P = 0.26; aOR 2.47, 95% CI 0.59 to 10.36, P = 0.22), LOS (OR 0.03, 95% CI −0.45 to 0.51; P = 0.90; aOR 0.03, 95% CI −0.47 to 0.54, P = 0.91), and cost of admission (OR −2438, 95% CI −6865 to 1989, P = 0.28; aOR −2196, 95% CI −6933 to 2539, P = 0.36) (Table 5).

Table 4.
Unadjusted baseline characteristics of diverticulitis in Crohn’s disease versus absence of IBD

Variable Crohn’s disease (n = 1090) No IBD (n = 218 725) P value
Age (SEM) 59.59 (1.06) 60.4 (0.09) 0.41
Female (%) 8251 (57) 126 860 (58) 0.73
Caucasian (%) 943 (86.5) 168 200 (76.9) 0.7
Black (%) 65 (5.97) 18 592 (8.5)
Hispanic (%) 60 (5.47) 24 060 (11)
Asian (%) 6 (0.5) 2056 (0.94)
Other (%) 16 (1.5) 787 (0.36)
COPD (%) 225 (20.64) 35 280 (16.13) 0.09
ESRD (%) 95 (8.72) 15 376 (7.03) 0.31
CHF (%) 65 (5.96) 10 914 (4.99) 0.49
Liver Disease (%) 55 (5.05) 7, 655 (3.5) 0.2
DMcx (%) 25 (2.29) 3981 (1.82) 0.6
HTN (%) 600 (55.05) 117, 324 (53.64) 0.67
CCI (%) 0.23
0 652 (59.82) 130 119 (59.5)
1 198 (18.8) 49 125 (22.46)
2 135 (12.4) 20 035 (9.15)
3 105 (9.63) 19 446 (8.89)
Hospital size 0.34
Small (%) 61 (5.56) 48 607 (22.22)
Medium (%) 61 (5.56) 70 305 (32.14)
Large (%) 968 (88.9) 99 811 (45.63)
Hospital region 0.75
Northeast (%) 225 (20.64) 47 748 (21.83)
Midwest (%) 250 (22.94) 49, 738 (22.74)
South (%) 460 (42.2) 85 390 (39.04)
West (%) 155 (14.22) 35 849 (16.39)
Insurance 0.06
Northeast (%) 473 (43.4) 93 439 (42.7)
Midwest (%) 93 (8.49) 20 691 (9.46)
South (%) 427 (39.15) 93 898 (42.93)
West (%) 97 (8.90) 10 697 (4.89)
Income 0.62
Medicare (%) 253 (23.20) 54 134 (24.75)
Medicaid (%) 289 (26.51) 60 368 (27.60)
Private insurance (%) 310 (28.44) 53 216 (24.33)
Self-pay (%) 238 (21.8) 51 007 (23.32)
  • Values are % except for age (mean + standard error mean).
  • CCI, Charlson comorbidity index; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; DMcx, complicated diabetes mellitus type 2; ESRD, end stage renal disease; HTN, hypertension; IBD, inflammatory bowel disease.

Table 5.
Effect of Crohn’s disease versus absence of IBD on diverticulitis hospitalization

Unadjusted odds ratio 95% CI P value Adjusted odds ratio 95% CI P value
Died 2.22 0.55 to 9.05 0.26 2.47 0.59 to 10.36 0.22
Length of stay 0.03 −0.45 to 0.51 0.90 0.03 −0.47 to 0.54 0.91
Cost of hospitalization −2438 −6865 to 1989 0.28 −2196 −6933 to 2539 0.36
  • CI, confidence interval; IBD, inflammatory bowel disease.


Diverticula typically present around the sigmoid colon, and when this is accompanied by left-sided IBD, the conditions may coexist.8 Patients can have a history of IBD with subsequent development of diverticulitis, as well as a history of IBD with induction of inflammation in asymptomatic diverticula.11, 19 However, the hospital burden of diverticulitis with pre-existing IBD has not been previously reported. There were 1815 patients admitted nationally for acute diverticulitis with pre-existing IBD in 2014. There were 33.5% more admissions for CD compared to UC, which is consistent with trends in the literature.8, 12, 13 Mucosal scarring in some UC patients may reduce the ability to form diverticula and could account for the decreased frequency of diverticulitis seen in the study.20 With regard to baseline characteristics, age was significantly different, while female gender and race were similar between the cohorts (Table 1).

Interestingly, there was a 26.5% increase in median LOS and 30.4% increase in cost of hospitalization with UC compared to CD. In addition, there were 50% more deaths with UC versus CD, which may be a result of emergent surgery.11 Overall, UC compared to CD was also associated with worse hospitalization outcomes on multivariate logistic regression. However, there was no significant difference in mortality.

Of the IBD subtypes, CD appears to have the more favorable hospitalization profile. Moreover, despite having 30% fewer patients, the UC cohort had 20 colectomies performed, with a longer and costlier hospital course. The CCI indicates that UC patients are not inherently more ill, and the outcome of this hospitalization is a result of events that occur during the course of the admission. Thus, the colectomies may be a reasonable explanation for the hospital measures seen above as mortality is typically higher in these patients.11 However, whether these surgeries occurred as a result of severe diverticular disease or UC warrants further investigation as it cannot be determined with the NIS database.

Given the above findings, an alternate analysis was conducted to compare CD hospitalization to the absence of IBD. Despite having 200× more patients, the population without IBD exhibited no significant difference among the LOS or cost of hospitalization. Multivariate logistic regression reflected these outcomes, demonstrating no association between the cohorts and increased mortality or hospitalization burden. There were colectomies performed in 0.5% of the population without IBD, so if this factor contributed to worsened hospitalization outcomes, it did not make as considerable an impact as in the UC cohort.

This is a meaningful study as hospitalization burden with these conditions is quite substantial14-16 and may differ based on the type of IBD involved. In this work, diverticulitis with simultaneous UC had a greater financial debt compared to a similar cohort with either CD or the complete absence of IBD. Colectomies, performed for severe manifestations of disease, likely have a prominent role in these outcomes. As colectomy is a known treatment in UC, its use as therapy may understandably prolong hospitalization. While it is possible that colectomies were also performed for severe diverticular disease, this information cannot be gathered from these data. It is important to note that the expensive and prolonged hospital course associated with this phenomenon has not been previously investigated in the literature. As such, the utility of this work is twofold: to raise awareness of conditions that may necessitate a higher level of care and the subsequent implications such a study will yield for resource management in hospitals.

The NIS has several strengths and limitations that warrant consideration. With health-related information from 20% of nonfederal hospitals, NIS has amassed a database that enables a representative study of the US population. These sample sizes are typically larger than hospital-funded studies; thus, the trends observed are difficult to dispute and provide a national overview of disease. However, NIS is an administrative database that is susceptible to coding inaccuracies.14 Indeed, the database is limited to those conditions that possess an ICD-9 code. Without this, there is no definitive way to identify a condition (i.e. Segmental Colitis Associated Disease, SCAD). Moreover, as laboratory values, imaging, and histology are not available, verification of the aforementioned conditions is not possible with this database (i.e. SCAD vs diverticular colitis). Thus, if the World Health Organization originally coded a condition as UC or diverticular colitis, the authors assumed it was an accurate characterization. In addition, the indications for a procedure are not supplied by NIS. Moreover, while multivariate logistic regression did account for most confounders (listed in the methods), there is a possibility that residual confounding still exists. Finally, this database is not designed to determine risk factors or causation. Thus, prospective trials will be necessary to further explore all possible etiologies and clinical applications of these findings.


In this national study, acute diverticulitis was examined with pre-existing IBD to determine if a difference in hospital outcome exists between UC and CD. There was a greater hospital burden observed in those with UC, which may be attributable to the colectomies that were performed. Moreover, there was a similar hospital burden among both those with CD and those without IBD, although for the latter, colectomies did not comprise as significant a proportion as for UC. The hospitalization outcomes of diverticulitis with concurrent IBD has not been presented in the literature, and this knowledge will assist clinicians in recognizing patients at higher risk of decompensation who will require greater resource utilization.


The authors would like to thank the Medicine Department for assistance with drafts of the manuscript.