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Diverticular Disease (Diverticulitis) vs. IBS (Irritable Bowel Syndrome)

Reviewed on 4/7/2020

Diverticular Diverticulitis IBS Irritable Bowel Related Articles

What's the Difference Between Diverticular Disease and IBS?

If a diverticulum becomes inflamed or infected or the area around the diverticulum is swollen, it is called diverticulitis.

Diverticulosis is a condition that describes small pouches (diverticula) in the wall of the digestive tract that occur 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.

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder. IBS is not the same as inflammatory bowel disease (IBD), a more serious condition that causes inflammation in the digestive tract and can result in severe complications.

  • 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 in (usually in the lower left side), bleeding, fever, nausea, vomiting, chills, constipation, and occasionally, diarrhea.
  • Symptoms of irritable bowel syndrome (IBS) include Symptoms of IBS include abdominal cramping or pain, bloating, gas, and changes in bowel movements (alternating periods of diarrhea and constipation).
  • 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 exact cause of IBS is unknown. IBS may be caused by dietary allergies or food sensitivities, and it has developed after episodes of gastroenteritis. Stress and hormonal changes (such as during menstruation) may worsen symptoms of IBS but do not cause the condition.
  • 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. Diverticulitis, which is more serious, is sometimes treated with medications, antibiotics, and in severe cases, surgery.
  • Treatment for IBS symptoms may include adding fiber to the diet, reducing stress and anxiety, eating regular balanced meals, reducing caffeine intake, exercising regularly, and quitting smoking.

What Is Diverticular Disease?

  • Diverticulosis is a condition that describes small pouches in the wall of the digestive tract that occur 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 a 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 irritable bowel syndrome or IBS? See Answer

What Is IBS?

  • Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder.
  • IBS is not the same as inflammatory bowel disease (IBD), a more serious condition that causes inflammation in the digestive tract and can result in severe complications.
  • Symptoms of IBS include
    • abdominal cramping or pain,
    • bloating,
    • gassiness, and
    • altered bowel habits (alternating periods of diarrhea and constipation).
  • The cause of irritable bowel syndrome is currently unknown. It is thought to result from a combination of abnormal gastrointestinal (GI) tract movements, increased awareness of bodily functions, and a disruption in the communication between the brain and the GI tract.
  • IBS-D is irritable bowel syndrome with diarrhea. Symptoms most common with IBS-D include:
    • Sudden urges to have bowel movements
    • Abdominal pain or discomfort
    • Intestinal gas (flatulence)
    • Loose stools
    • Frequent stools
    • Feeling of being unable to completely empty bowels
    • Nausea
  • IBS-C is irritable bowel syndrome with constipation. Symptoms most common with IBS-C include:
    • Hard, lumpy stools
    • Straining during bowel movements
    • Infrequent stools
  • There is a new blood test that may help doctors diagnose some forms of irritable bowel syndrome.
  • IBS is diagnosed by exclusion, which means a doctor considers other alternatives first, performing tests to rule out other medical problems.
  • Home remedies for IBS include avoiding certain foods that "trigger" or worsen diarrhea, bloating and gas such as cruciferous vegetables (for example, cauliflower, wasabi, kale, and broccoli), and legumes (for example, black beans, edamame, soy nuts, and fava beans).
  • Other home remedies to relieve symptoms of IBS include adding fiber to the diet, drinking plenty of water, avoiding soda, eating smaller meals, and eating more low fat and high carbohydrate foods.
  • There is currently no known cure for IBS. Medical treatment for irritable bowel syndrome includes antispasmodic medicines, antidiarrheal medicines, antidepressants, laxatives, and other drugs.
  • Irritable bowel syndrome is a chronic (long-term) disease, and symptoms usually recur.
  • Irritable bowel syndrome has also been called spastic colon, functional bowel disease, and mucous colitis though. IBS is not a true "colitis." The term colitis refers to a different group of conditions such as ulcerative colitis, Crohn's disease, microscopic colitis, and ischemic colitis. These are other types of bowel disease.

What Are the Symptoms of Diverticular Disease vs. IBS?

Diverticular Disease

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 health-care professional.
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


IBS affects each person differently. The hallmark of IBS in adults and children is abdominal discomfort or pain. The following signs and symptoms also are common:
  • Abdominal cramping and pain that are relieved with bowel movements
  • Alternating periods of diarrhea and constipation

Those who mostly have diarrhea as a symptom are considered to have IBS with diarrhea (IBS-D), characterized by sudden urges to have bowel movements, along with loose stools, frequent stools, abdominal pain and discomfort, gas, and the feeling of being unable to completely empty the bowels.

In severe cases of IBS-D, individuals may lose control of their bowels.Those who mostly have constipation as a symptom are considered to have IBS with constipation (IBS-C), characterized by passage of hard, lumpy stools, straining during bowel movements, and infrequent stools. Symptoms include:

  • Change in the stool frequency or consistency
  • Gassiness (flatulence)
  • Passing mucus from the rectum
  • Bloating
  • Abdominal distension
  • Loss of appetite
Though not a symptom of IBS, indigestion affects up to 70% of people with IBS.
The following are NOT signs and symptoms or characteristics of IBS (but should still be brought to the attention of a health-care professional since they may be signs and symptoms of other conditions):
  • Blood in stools or urine
  • Black or tarry stools
  • Vomiting (rare, though may occasionally accompany nausea)
  • Pain or diarrhea that interrupts sleep
  • Fever
  • Weight loss

What Causes Diverticular Disease vs. IBS?

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 to in the diet keep stool soft and moving easily through the digestive tract.
  • This is how fiber prevents constipation.


IBS is not contagious, inherited, or cancerous. It occurs more often in women than in men, and the onset occurs before the age of 35 in about half of the cases. IBS occurs in 5% to 20% of children.

  • IBS also has developed after episodes of gastroenteritis.
  • It has been suggested that IBS is caused by dietary allergies or food sensitivities, but this has not been proven.
  • Genetics also is suggested as a potential cause of IBS, but so far a hereditary link has not been found. Symptoms of irritable bowel syndrome may worsen during periods of stress or during menstruation, but these factors are unlikely to be the cause that leads to the development of IBS.

What Is the Treatment for Diverticular Disease vs. IBS?

Diverticular Disease

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 go away. Foods high in fiber include:
    • Whole-grain cereals and breads
    • 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 actually 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 health-care 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.


Most people with IBS have symptoms only occasionally and the following measures may treat or soothe symptoms during a flare:

  • Add fiber to the diet: Fiber theoretically expands the inside of the digestive tract, reducing the chance it will spasm as it transmits and digests food. Fiber also promotes regular bowel movements, which helps reduce constipation. Fiber should be added gradually, because it may initially worsen bloating and gassiness. People with IBS-D should look for foods with more soluble fiber, the type that takes longer to digest (such as that found in oats, beans, barley, peas, apples, carrots, and citrus fruits).
  • Reduce stress and anxiety: Stress and anxiety may cause IBS "flares." Health-care professionals may offer specific advice on reducing stress. The following may help reduce stress and problems associated with IBS:
    • Eat regular balanced meals.
    • Reduce caffeine intake.
    • Exercise may help reduce stress.
    • Smoking may worsen symptoms of IBS, which is another good reason to quit.

Other home remedies to soothe and lessen IBS symptoms include:

  • Increase fiber in the diet
  • Drink plenty of water
  • Avoid soda, which may cause gas and abdominal discomfort
  • Eat smaller meals to help lessen the incidence of cramping and diarrhea.
  • Low fat and high carbohydrate meals such as pasta, rice, and whole grain breads may help IBS symptoms (unless the person has celiac disease).
  • Antispasmodic drugs
  • Antispasmodic medicines, such as dicyclomine (Bemote, Bentyl, Di-Spaz) and hyoscyamine (Levsin, Levbid, NuLev), are sometimes used to treat symptoms of irritable bowel syndrome. Antispasmodic medicines help slow the movements of the digestive tract and reduce the chance of spasms. They may have side effects and are not for everyone. Other treatment plans are available, depending on the symptoms and condition.
  • Antidiarrheal drugs
  • Antidiarrheal medicines, such as loperamide (Imodium), a kaolin/pectin preparation (Kaopectate), and diphenoxylate/atropine (Lomotil), are sometimes used when diarrhea is a major feature of IBS. Do not take these on a long-term basis without first consulting a doctor.
  • Antidepressants
  • Antidepressants may be very effective in smaller doses than those typically used to treat depression. Imipramine (Tofranil), amitriptyline (Elavil), nortriptyline (Pamelor), and desipramine (Norpramin) are some commonly used medicines that may alleviate irritable bowel syndrome symptoms. Some other antidepressants are more commonly prescribed when depression and IBS coexist.

The following medications are typically reserved for patients with symptoms that do not improve with the previously mentioned treatments:

  • Alosetron (Lotronex) is a restricted drug approved only for short-term treatment of women with severe, chronic, diarrhea-predominant IBS (IBS-D) who have failed to respond to conventional IBS therapy. Fewer than 5% of people with irritable bowel syndrome have the severe form, and only a fraction of people with severe IBS have the diarrhea-predominant type. Alosetron was removed from the United States market but was reintroduced with new restrictions approved by the FDA in 2002. Physicians must be registered with the pharmaceutical manufacturer in order to prescribe the medication. Serious and unpredictable gastrointestinal side effects (including some that resulted in death) were reported in association with its use following its original approval. The safety and efficacy of alosetron has not been sufficiently studied in men; therefore, the FDA has not approved the drug for treatment of IBS in men.
  • Rifaximin (Xifaxan) is an antibiotic medication for IBS-D that works by reducing or altering gut bacteria, and it can improve symptoms of bloating and diarrhea after a 10 to 14 day course of treatment. Some patients require retreatment at higher doses for symptom relief.
  • Eluxadoline (Viberzi) is another newer medication for IBS-D that helps reduce abdominal pain and improves stool consistency in adults.
  • Linaclotide (Linzess) is a kind of drug that relieves constipation and pain for some adults with irritable bowel syndrome (IBS). In drug trials, people with IBS with constipation (a subtype of IBS called IBS-C) had more frequent and better bowel movements and less abdominal pain after taking daily doses of Linzess. The drug often began working within the first few days of treatment.
  • Lubiprostone (Amitiza) is a type of laxative used to treat severe irritable bowel syndrome with constipation (IBS-C) in women who are at least 18 years of age. It is a capsule taken orally, twice a day with food. It is used to relieve stomach pain, bloating, and straining; and produce softer and more frequent bowel movements in people who have chronic idiopathic constipation.
  • Tegaserod (Zelnorm) was a medication used to treat IBS but was removed from the market in 2008 due to increased risk of heart attack, stroke, and ischemic colitis.
  • New medications for IBS-D are also being developed or are in clinical trials. Those that are most promising include:
  • Serotonin synthesis inhibitors may help reduce pain and improve stool consistency
  • Ramosetron, similar to alosetron (Lotronex). This is reported to relieve symptoms with less constipation.
  • Spherical carbon adsorbent offers short-term relief from pain and bloating, but no improvement in stool consistency.
  • Benzodiazepine receptor modulator (dextofisopam) has the potential to reduce colonic motility and gut sensitivity reactions in response to stress.
  • Peripheral k-agonist (asimadoline, a kappa-opioid agonist) is in clinical trials and it shows reduced pain, urgency and stool frequency.

Diet and lifestyle changes are important in decreasing the frequency and severity of IBS symptoms. The first thing your doctor may suggest is to keep a food diary. This will help you figure out foods that trigger your symptoms.

  • Limit foods that contain ingredients that can stimulate the intestines and cause diarrhea, such as:
    • Caffeine
    • Alcohol
    • Dairy products
    • Fatty foods
    • Foods high in sugar
    • Artificial sweeteners (sorbitol and xylitol)
  • Some vegetables (cauliflower, broccoli, cabbage, Brussels sprouts) and legumes (beans) may worsen bloating and gassiness and should be avoided.
  • A high fiber diet may lessen symptoms of constipation.
  • Drink plenty of water, and avoid carbonated drinks such as soda, which may cause gas and discomfort.
  • Eat smaller meals and eat slowly to help reduce cramping and diarrhea.
  • Low fat, high carbohydrate meals such as pasta, rice, and whole-grain breads may help (unless you have celiac disease).
  • Probiotic supplements such as lactobacillus acidophilus or prebiotics may help alleviate IBS symptoms including abdominal pain, bloating, and bowel movement irregularity.
  • A diet low in FODMAPs (Fermentable Oligo-saccharides, Di-saccharides, Mono-saccharides And Polyols), a group of short-chain carbohydrates, may help relieve IBS symptoms. Consult your doctor for more information.


Digestive Disorders: Common Misconceptions See Slideshow

What Is the Prognosis for Diverticular Disease vs. IBS?

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 a 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 health-care professional at the first sign of recurring symptoms.


Because irritable bowel syndrome is a chronic (long-term) disease, symptoms usually return from time to time. This may be influenced by factors such as stress, diet, or other environmental causes. No known treatment cures IBS. Multiple factors may play a role in aggravating IBS, so it is difficult to predict what triggers may make IBS worse in a particular person. Establishing a good relationship with a health-care professional may help alleviate concerns over symptoms and allow rapid recognition of changing or worsening symptoms.

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Reviewed on 4/7/2020
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