Diverticulitis vs. Ulcerative Colitis (UC)

What Is the Difference Between Diverticulitis and Ulcerative Colitis?

Diverticulosis is a condition that describes small pouches in the wall of the digestive tract that occurs when the inner layer of the digestive tract bulges through weak spots in the outer layer. When these diverticula become inflamed or infected, diverticulitis can develop.

Ulcerative colitis (UC) is an acute or chronic inflammation of the membrane that lines the colon (the large intestine or large bowel). The inflammation occurs in the innermost layer of the colon and may result in the formation of sores (ulcers). Ulcerative colitis rarely affects the small intestine except for the lowermost section, called the terminal ileum. Ulcerative colitis is a type of inflammatory bowel disease (IBD).

  • Diverticulosis patients may have no symptoms. When symptoms do occur they can include abdominal pain, bloating, constipation (less often, diarrhea), and cramping. Symptoms of diverticulitis can include abdominal pain (usually in the lower-left side), bleeding, fever, nausea, vomiting, chills, constipation, and occasionally, diarrhea.
  • Symptoms of ulcerative colitis include abdominal pain, diarrhea, rectal bleeding, the urge to have a bowel movement, lack of appetite, fever, and fatigue.
  • Diverticulosis is thought to be caused by increased pressure on the intestinal wall from inside the intestine. Diverticulosis in developed countries is blamed largely on a diet low in fiber.
  • The cause of ulcerative colitis is unknown. The body's immune system may react to a virus or bacteria, causing ongoing inflammation in the intestinal wall. Emotional stress or food sensitivities may trigger symptoms, causing a flare-up. Risk factors include genetic or family history, infectious agents or environmental toxins, changes in the immune system, and smoking.
  • A high-fiber diet is the mainstay of diverticulosis and diverticulitis prevention. Talk to your doctor about foods to eat and foods to avoid to manage the symptoms. More serious diverticulitis is sometimes treated with medications, antibiotics, and in severe cases, surgery.
  • Treatment for ulcerative colitis depends on the severity of the disease. Most people are treated with medications. If there are significant bleeding, infection, or complications, surgery may be required to remove the diseased colon. Surgery is the only cure for ulcerative colitis.

What Is Diverticular Disease?

  • Diverticulosis is a condition that describes small pouches in the wall of the digestive tract that occurs when the inner layer of the digestive tract bulges through weak spots in the outer layer. When these diverticula become inflamed, that is called diverticulitis.
  • One of the main causes of diverticulosis is a diet low in fiber.
  • Many people with diverticulosis have no symptoms. When symptoms do occur they can include:
    • Pain in the abdomen
    • Bloating
    • Constipation (less often, diarrhea)
    • Cramping
  • Diverticulitis is more serious and symptoms can include:
    • Pain in the abdomen (usually in the lower-left side)
    • Bleeding
    • Fever
    • Nausea
    • Vomiting
    • Chills
    • Constipation
    • Occasionally diarrhea
  • Diagnosis of diverticulosis/diverticulitis is made by a physical exam, which may include a digital rectal examination, blood tests, X-rays or CT scans of organs in the abdomen, a colonoscopy, or flexible sigmoidoscopy.
  • Treatment for diverticulosis includes a diet high in fiber, fiber supplementation if needed, plenty of fluids, and exercise.
  • Diverticulitis also is treated with antibiotics and sometimes surgery.

What Is Ulcerative Colitis (UC)?

  • Ulcerative colitis (UC) is an acute or chronic inflammation of the membrane that lines the colon (the large intestine or large bowel). The inflammation occurs in the innermost layer of the colon and may result in the formation of sores (ulcers). Ulcerative colitis rarely affects the small intestine except for the lowermost section, called the terminal ileum.
  • The inflammation makes the colon empty frequently causing diarrhea. Ulcers form in places where the inflammation has killed the cells lining the colon. The ulcers bleed and produce pus and mucus.
  • Symptoms of ulcerative colitis include abdominal pain, diarrhea, rectal bleeding, a recurrent urge to have a bowel movement (tenesmus), lack of appetite, fever, and fatigue.
  • Abdominal pain, diarrhea, and bloody bowel movements are the hallmark of the disease. The disease initially causes inflammation in the rectum and may gradually spread to involve the whole colon. If just the rectum is involved, it is referred to as ulcerative proctitis.
  • Ulcerative colitis is one of the inflammatory bowel diseases (IBD), the other is Crohn's disease.
    • Ulcerative colitis may be difficult to diagnose because its symptoms may mimic other intestinal disorders such as irritable bowel syndrome.
    • Crohn's disease differs from ulcerative colitis in several ways: it causes inflammation deeper within the intestinal wall, it may occur anywhere in the digestive tract, from the mouth to the anus, and is patchy in nature. While Crohn's disease most often occurs in the small intestine, there can be scattered lesions throughout the gastrointestinal tract. Ulcerative colitis affects only the colon and progresses proximally from the rectum in a continuous manner to potentially involve the rest of the colon.
    • There are an estimated 1-1.3 million people in the United States who suffer from inflammatory bowel disease. Ulcerative colitis is generally found in younger people and the diagnosis is often made in people between the ages of 15 and 30. Less frequently, the disease can also occur in people later in life, even past the age of 60. It affects both men and women equally, and there is a familial predisposition to its development. Those of Jewish heritage have a higher incidence of ulcerative colitis.

What Are the Signs and Symptoms of Diverticular Disease vs. Ulcerative Colitis?

Symptoms and Signs of Diverticulosis

Most people with diverticulosis have no symptoms. When symptoms do occur, they are usually mild and include:
  • Pain in the belly (abdomen)
  • Bloating
  • Constipation (less often, diarrhea)
  • Cramping

These symptoms are nonspecific. This means that similar symptoms are seen in many different digestive disorders. They do not necessarily mean that a person has diverticulosis. If an individual has these symptoms, he or she should see a healthcare professional.

Symptoms and Signs of Diverticulitis

Diverticulitis is a more serious condition and causes symptoms in most people with the condition that include:

  • Pain in the abdomen, usually in the lower-left side
  • Bleeding, bright red or maroon blood may appear in the stool, in the toilet (a symptom of rectal bleeding), or on the toilet paper. Bleeding is often mild and usually stops by itself; however, it can become severe.
  • Fever
  • Nausea
  • Vomiting
  • Chills
  • Constipation (less often, diarrhea)
If diverticulitis is not treated promptly it can develop some very serious complications. A complication is suggested by any of these symptoms:
  • Worsening abdominal pain
  • Persistent fever
  • Vomiting (no food or liquid can be tolerated)
  • Constipation for an extended period of time
  • Burning or pain during urination
  • Bleeding from the rectum

Symptoms and Signs of Ulcerative Colitis (UC)

Common symptoms of ulcerative colitis include the following:
  • Frequent loose bowel movements with or without blood
  • The urgency to have a bowel movement (tenesmus) and bowel incontinence (loss of bowel control)
  • Lower abdominal discomfort or cramps
  • Fever, lethargy, and loss of appetite
  • Weight loss with continuing diarrhea
  • Anemia due to bleeding with bowel movements
Because inflammatory bowel disease may be caused by a defect in the immune response system, other body organs may be involved, including for example:

What Causes Diverticular Disease vs. Ulcerative Colitis?

Causes of Diverticular Disease

Diverticulosis is thought to be caused by increased pressure on the intestinal wall from inside the intestine.

  • As the body ages, the outer layer of the intestinal wall thickens. This causes the open space inside the intestine to narrow. Stool (feces) moves more slowly through the colon, increasing the pressure.
  • Hard stools, such as those produced by a diet low in fiber or slower stool "transit time" through the colon can further increase the pressure.
  • Frequent, repeated straining during bowel movements also increases the pressure and contributes to the formation of diverticula.

Diverticulosis in developed countries is blamed largely on a diet low in fiber.

  • Fiber is found in fruits and vegetables, whole grains, and legumes (beans, peas, and lentils).
  • There are two types of fiber; soluble (dissolves in water) and insoluble.
    • Soluble fiber forms a soft gel-like substance in the digestive tract.
    • Insoluble fiber passes through the digestive tract nearly unchanged.
  • Both are necessary for the diet to keep stool soft and moving easily through the digestive tract.
  • This is how fiber prevents constipation.

Causes of Ulcerative Colitis (UC)

The cause of ulcerative colitis is uncertain. Researchers believe that the body's immune system reacts to a virus or bacteria, causing ongoing inflammation in the intestinal wall. Although UC is considered to be a problem with the immune system, some researchers believe that the immune reaction may be the result, not the cause, of ulcerative colitis.

While ulcerative colitis is not caused by emotional stress or food sensitivities, these factors may trigger symptoms in some people.

Risk factors for inflammatory bowel disease include:

  • Genetic or family history: There is a high similarity of symptoms among identical twins, particularly with Crohn's disease. A person has a greater risk of getting the disease if a first-degree relative such as a parent or a sibling is affected.
  • Infectious agents or environmental toxins: No single agent has been associated consistently as a cause of inflammatory bowel disease. Viruses have been found in tissue samples from people with inflammatory bowel disease, but there is no incriminating evidence that these are the sole cause of the disease.
  • Immune system: Several changes in the immune system have been identified as contributing to inflammatory bowel disease, but none are proven to specifically cause either ulcerative colitis or Crohn's disease.
  • Smoking: Smokers increase their risk of developing Crohn's disease by twofold. In contrast, smokers have only one-half the risk of developing ulcerative colitis.
  • Psychological factors: Emotional factors do not cause inflammatory bowel disease. However, psychological factors may modify the course of the disease. For example, stress may worsen symptoms or cause a relapse and may also affect the response to therapy.

What Are the Treatments, Complications, and Risk of Cancer for Diverticular Disease vs. Ulcerative Colitis?

Diverticular Disease Treatment

A high-fiber diet is the mainstay of diverticulosis and diverticulitis prevention.

  • Start a high-fiber diet because it will decrease the risk of complications and the accompanying symptoms; however, will not make the diverticula a person has gone away. Foods high in fiber include:
    • Whole-grain cereals and bread
    • Fruits (apples, berries, peaches, pears)
    • Vegetables (squash, broccoli, cabbage, and spinach)
    • Beans, peas, and lentils.
  • Drinking plenty of fluids will also help the stool stay soft and pass quickly to prevent constipation and decrease the risk for diverticulosis.
  • Get plenty of physical activity to keep bowels functioning properly.

In the past patients with diverticulosis/diverticulitis were told that foods to avoid included seeds, corn, and nuts because it was thought fragments of these foods would get stuck in the diverticula and cause inflammation. However, current research has not found this to be the case, and the fiber content of such foods may benefit individuals with diverticulosis/diverticulitis. Discuss your diet or potential diet changes with your doctor.

Treatment for diverticulitis depends on the severity of the condition.

  • Simple cases can be treated by a healthcare professional at his or her office, and by a patient following a high fiber diet.
  • Treatment for uncomplicated cases usually consists of antibiotics and bowel rest. This usually involves two to three days of bowel rest, taking in only clear fluids (no food at all), so the colon may heal without having to work.
  • Complicated cases typically involve severe pain, fever, or bleeding. If an individual has any of these symptoms, he or she will probably be admitted to the hospital.

Treatment consists of IV or oral antibiotics, bowel rest, and possibly surgery.

If diverticulitis attacks are frequent or severe, the doctor may suggest surgery to remove a part of the patient's colon.

  • As with any surgery, there are risks the patient should discuss with his or her doctor.
  • Sometimes the operation requires at least two separate surgeries on different occasions.

Ulcerative Colitis Treatment

Treatment for ulcerative colitis depends on the severity of the disease. Most people are treated with medication. If there are significant bleeding, infection, or complications, surgery may be required to remove the diseased colon. Surgery is the only cure for ulcerative colitis.

Ulcerative colitis may affect patients in different ways, and treatment is adjusted to meet the needs of the specific patient. Emotional and psychological support is also important.

The symptoms of ulcerative colitis come and go. Periods of remission, in which symptoms resolve, may last for months or years before relapsing. Patients and physicians need to decide together whether medications will be continued during remission times. In some patients, it may be the case that the medications keep the disease under control, and stopping them will cause a relapse.

Ulcerative colitis is a lifelong illness and cannot be ignored. Routine medical check-ups are necessary and scheduled colonoscopies are important to monitor the health of the patient and to make certain that the ulcerative colitis is under control and not spreading.

Complications

  • Significant complications may occur with an acute flare of ulcerative colitis including dehydration, electrolyte abnormalities from profuse diarrhea, and anemia from rectal bleeding.
  • A surgical emergency exists if the colon becomes weakened at a site of inflammation and perforates, spilling bowel contents into the abdominal cavity.
  • Other organs of the body may become inflamed, including the eyes, muscles, joints, skin, and liver.
  • Primary sclerosing cholangitis may be associated with severe ulcerative colitis. In this condition, the ducts that drain bile from the liver become inflamed and scarred.

The Risk of Cancer

  • Colon cancer is the major long-term complication of ulcerative colitis.
  • The risk of colon cancer is estimated to be 2% after 10 years, 8% after 20 years, and 18% after 30 years of the disease.
  • The risk is greater for those whose entire colon is affected as opposed to those who have only a small segment involved such as the rectum.
  • Screening colonoscopy is recommended 8 to 10 years after the onset of the initial symptoms to look for cancer or pre-cancerous changes in the lining of the colon.
  • Colonoscopy should be repeated routinely, the frequency depends upon whether a part or all of the colon is involved with the disease and how long the disease has been present.

Associated illnesses

  • Primary sclerosing cholangitis may be associated with severe ulcerative colitis. In this condition, the ducts that drain bile from the liver become inflamed and scarred.
  • Iritis or uveitis. These diseases indicate inflammation of the eye.
  • Ankylosing spondylitis, a disease that causes inflammation in the joints between the vertebrae in the spine and the joints between the spine and the pelvis.
  • Erythema nodusum, in which the skin becomes inflamed.

Diet to Control Diarrhea

Mild diarrhea may be controlled with diet.

  • Clear fluids for 24 hours allows the colon to rest and will usually resolve the loose bowel movements.
  • Milk products and fatty, greasy foods should be avoided for a few days.
  • An increase in fluid intake is encouraged to prevent dehydration. Urine output can be used as a gauge of hydration. If the urine is yellow and concentrated, more fluid may be required.

Proper Nutrition

Proper nutrition is important for a person with ulcerative colitis.

  • Spicy or high-fiber foods may need to be eliminated especially when the diarrhea phase is active.
  • Keep a food diary to help find foods that cause problems.
  • A well-balanced diet is always a smart choice.

Counseling and education are important for both patient and family; a better understanding of how ulcerative colitis affects the body will allow the patient and doctor to work together to control the symptoms.

Foods that Trigger and Cause Flare-Ups

Foods do not cause ulcerative colitis, but certain food groups can cause symptoms to flare. Often it is a process of trial and error to find what foods need to be avoided.

  • Dairy foods: Some patients with ulcerative colitis may also have lactose intolerance that can make diarrhea worse.
  • High fiber is often recommended to aid with bowel regularity but may make diarrhea worse in ulcerative colitis. Whole grains, vegetables, and fruit may worsen pain, gas, and diarrhea. Finding foods that are the culprit may require a trial and error approach.
  • Trial and error may also find other "gassy" foods like caffeine and carbonated beverages.
  • Small, frequent meals may be helpful in controlling symptoms. Grazing during the day may be better than 2 or 3 large meals.
  • Dehydration: The body can lose a significant amount of water with diarrhea, and drinking plenty of fluids to replace that loss is very important.
  • Well rounded diet: A less than rounded diet may require vitamin and mineral supplements, and visiting with a dietician is often an important step in maintaining good nutrition while controlling the symptoms.

What Is the Prognosis for Diverticulitis vs. Ulcerative Colitis; Can They Be Cured?

Diverticular Disease

Most people recover fully after treatment. If not treated promptly, however, diverticulitis can lead to the following more serious conditions and complications:

  • Perforation: A hole in the intestine caused when the diverticular pouch bursts because of increased pressure and infection within the intestine.
  • Peritonitis: A more serious infection of the abdominal cavity that often occurs after perforation, when the contents of the intestine leak out into the abdominal cavity (peritoneum) outside of the intestine.
  • Abscess: A pocket of infection that is very difficult to cure with antibiotics.
  • Fistula: An abnormal connection between the colon and another organ that occurs when the colon damaged by infection comes in contact with another tissue, such as the bladder, the small intestine, or the inside of the abdominal wall, and sticks to it. Fecal material from the colon can then get into the other tissue. This often causes severe infection. If fecal material gets into the bladder, for example, the resulting urinary tract infection can become recurrent and very difficult to cure.
  • Blockage or obstruction of the intestine
  • Bleeding in the intestine

Of the people who are admitted to a hospital for diverticulitis, some develop complications that require surgery.

Individuals younger than 40 years of age who have depressed immune systems from medications or other illnesses have a greater chance of having complications and having to undergo surgery.

Approximately one-half of people who have diverticulitis will have a relapse within seven years after the condition is treated and in remission. The second episode may be worse than the first. See a healthcare professional at the first sign of recurring symptoms.

Ulcerative Colitis

  • Ulcerative colitis is not a fatal illness, but it is a lifelong illness.
  • Most people with ulcerative colitis continue to lead normal, useful, and productive lives, even though they may need to take medications every day, and occasionally need to be hospitalized.
  • Maintenance medication has been shown to decrease flare-ups of ulcerative colitis.
  • Surgery may be required in some patients, but it is not required in every patient with ulcerative colitis.
  • Routine cancer screening is a must for those who do not undergo surgical removal of the colon.
References

Bogardus ST. What do we know about diverticular disease? A brief overview. Journal of Clinical Gastroenterology. 2006;40:S108–S111

Pemberton, JH, MD, et al. Acute colonic diverticulitis: Medical management. UpToDate. Mar 2020.
<http://www.uptodate.com/contents/acute-colonic-diverticulitis-medical-management>

Pemberton, JH,, MD, et al. Patient information: Diverticular disease (Beyond the Basics). UpToDate. Mar 2020.
<http://www.uptodate.com/contents/diverticular-disease-beyond-the-basics>

Shahedi, K. MD. "Diverticulitis." Medscape. Aug 06, 2020.
<http://emedicine.medscape.com/article/173388-overview>

Ulcerative Colitis. Medscape. Updated: Jul, 26, 2019.
<https://emedicine.medscape.com/article/183084-overview>