Irritable bowel syndrome (IBS) symptoms can also be caused by other conditions and therefore, diagnosis aims to confirm IBS so that other pathological conditions are ruled out. At the same time, a more pronged and focused treatment can be given to the patient.
You should know that IBS does not cause any damage to the intestines or other organs of the body and neither is it life-threatening. However, it can ruin the patient’s quality of life and interfere with daily activities.
Differential diagnosis
Irritable bowel syndrome (IBS) can often be mistaken for other gut diseases that present with similar symptoms. Please note in IBS, there is no damage or pathology in the GI tract while these other conditions exhibit clear pathological changes.
Such conditions include:
Inflammatory bowel diseases (IBD). IBD develops because the body’s immune system mistakenly attacks the intestines causing damage and chronic inflammation of the GI tract. Ulcerative colitis and Crohn’s disease are two examples of IBD. Besides having symptoms similar to those of IBS, these diseases may likely produce fever, bloody stools, and unexplained weight loss. The risk of colon cancer is also increased in IBD.
Diverticulitis. Diverticulitis develops when small diverticula (pouches) develop in the wall of the large intestine and become inflamed. This causes pain, fever, and other digestive symptoms.
Celiac disease. Celiac disease is an autoimmune disorder of the digestive system triggered by eating gluten foods. Gluten is a protein found in wheat, barley, and other grains. Due to the intestinal damage caused, GI tract symptoms develop such as diarrhea, bloating, weight loss, or anemia.
Lactose intolerance. Lactose intolerance develops when your body cannot tolerate lactose, a sugar present in milk and milk products. Common symptoms include abdominal pain or discomfort, diarrhea or constipation, bloating, and the formation of excess gases.
Colon cancer. Cancer of the colon presents with abdominal pain or discomfort, change in the nature and frequency of bowels, rectal bleeding, improper bowel evacuation, and fatigue.
Diagnosis
There is no specific blood test or imaging test to diagnose IBS. Symptoms are assessed and diagnosis is made using the new Rome IV criteria.
The Rome IV criteria for IBS are and I quote:
“Recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following criteria:
Related to defecation Associated with a change in frequency of stool Associated with a change in form (appearance) of stool * Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis”
The American College of Gastroenterology (ACG) recommends a positive diagnostic strategy to diagnose IBS and this strategy should be such as to rule out other similar conditions.
This strategy includes a physical exam, laboratory tests, and imaging tests to rule out more serious problems.
Certain alarming symptoms and signs can warn the clinician of other serious conditions. They include:
The onset of symptoms after the age of 50 years or even 45 years. Most people with IBS develop their first symptoms before the age of 40 and IBS is less likely to begin in people above 50 years of age.
Visible blood in the stool
Black stools (Malena) indicating occult blood in stools that can be suggestive of upper GI tract pathology
Unexplained weight loss
Family history of IBD or colon cancer
Lab tests for IBS
As stated above, there is no specific test to diagnose IBS. Lab tests are done to rule out other conditions, which help to confirm the diagnosis of IBS.
A confirmed diagnosis will ensure that you get proper treatment, supportive and pharmacological, in the right dose.
A complete blood count to check for anemia and infection
Lactose intolerance tests to rule out your intolerance to lipase, a sugar found in milk and dairy products
A blood test called a C-reactive protein (CRP) to rule out inflammatory bowel disease
Testing stools for bacterial and parasitic infection (like giardiasis) and to rule out intestinal infection.
Testing for food sensitivity if there are consistent GI tract disturbances from eating a certain food. This will help rule out malabsorption syndrome.
Imaging tests
To be sure that you do not have another condition that mimics IBS, such as inflammatory bowel disease (IBD) or diverticulitis, your doctor will order some imaging procedures and tests.
A colonoscopy allows for the gastroenterologist to get a direct view of the inside of your entire large intestine with the help of the colonoscope, which has a camera attached. In IBS, the findings of the colonoscopy will not show anything significant. It is done to rule out other pathological conditions that mimic IBS.
A computed tomography (CT) scan of the abdomen will provide detailed images of the structures and organs inside your abdomen and will help to rule out any tumors, infections, cysts, and any other problems with the organs that could be causing abdominal symptoms.
In an upper endoscopy, a camera at the end of the endoscope allows your gastroenterologist to view your upper digestive tract and to rule out causes of occult blood in the stools if present. During an endoscopy, a tissue sample (biopsy) may be collected. An endoscopy is very helpful to rule out celiac disease.
USG abdomen and pelvis helps to rule out ovarian cancer
Once other conditions, as mentioned in differential diagnosis, have been ruled out and the criteria of the Rome IV criteria are satisfied, a confident diagnosis of IBS can be declared and the proper treatment started.
Management of IBS
There is no permanent cure for IBS. Treatment focuses on giving relief from symptoms whenever there is a flare-up of the bowel symptoms.
Treatment will vary depending on what your complaints are. For example, if you have diarrhea, you will given medication to stop your diarrhea; if you have constipation, you will be given laxatives to clear your bowels.
However, some management options remain common. These include dietary modifications, lifestyle changes, certain medications, cognitive behavioral therapy, and some alternative therapies.
In July 2021, the British Society of Gastroenterology (BSG) published certain guidelines for the management of patients with IBS. They advocate the following guidelines:
Dietary restrictions
Identify and avoid foods that trigger your symptoms. This strategy will improve your symptoms because many people experience worsening of their symptoms after consuming certain foods and beverages. However, these triggers vary from person to person.
Doctors recommend the Low FODMAP diet for people with IBS. It consists of reducing or avoiding certain foods that contain carbohydrates that are difficult to digest.
These carbohydrates are called FODMAPs. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols.
While the FODMAP diet is healthy for most people, those with digestive problems like IBS should refrain from eating FODMAP foods because they are known to cause common digestive issues like bloating, gas, stomach pain, diarrhea, and constipation in those who are sensitive to them.
Examples of foods that contain FODMAPS and which people with IBS should avoid or restrict are:
Foods high in fructose such as apples, pears, dried fruits, mangoes, watermelons, cherries, and their fruit juices
Honey and foods that contain corn syrup
Vegetables such as asparagus, beans, cabbage, cauliflower, garlic, lentils, mushrooms, and onions
Avoid dairy products if you are lactose intolerant because they can cause gas, bloating, and diarrhea.
Similarly, if you are gluten-sensitive, avoid foods containing wheat such as cereal, grains, pasta, and processed foods because they can trigger symptoms like diarrhea and bloating.
Some other common foods that can aggravate symptoms include fried foods, spicy foods, fatty foods, chocolate, and those with too much fiber. Some high-fiber foods that are hard to digest include beans, cabbage, broccoli, cauliflower, brussels sprouts, and dried fruit.
Carbonated and caffeinated beverages, like coffee, tea, and energy drinks stimulate the smooth muscles in the gastrointestinal tract and lead to increased bowel movements.
Keep a food journal and make a note of which symptoms onset after eating what foods. Take the help of a dietitian to help you formulate a dietary plan. He will identify what foods you are sensitive to and formulate a special diet for you by the elimination method.
Dietary recommendations. What you should eat
You should eat fiber. Fiber is of two types: soluble and insoluble. Soluble fiber such as ispaghula, is good for relieving your IBS symptoms such as constipation and abdominal pain. you should, however, avoid insoluble fiber foods such as wheat bran because it may exacerbate symptoms.
However, initially soluble fiber can cause bloating and to avoid this you should start consuming it with a low dose of 3–4 g/day and build up gradually to prevent bloating.
Doctors recommend that people with IBS get 20–35 grams of soluble and non-fermentable fiber daily. Examples include carrots, green peas, potatoes, oatmeal, nuts, and bananas.
Increase your water and fluid intake to at least 12 to 14 cups every day. The benefits are tremendous.
Eat smaller more frequent meals regularly at about the same time. Do not miss meals and do not leave long gaps between meals.
OTC medications for IBS
Your healthcare provider will advise medication according to your symptoms. They will include smooth muscle relaxants, anti-diarrheal medications, laxatives, antibiotics, and low-dose antidepressants. They may be those that are available over-the-counter (OTC) and some may be available by prescription.
Some commonly used OTC options include:
Bismuth subsalicylate (Kaopectate) and loperamide (Imodium) give relief from diarrhea. However, these drugs will not help relieve other symptoms like abdominal pain.
OTC laxatives like Metamucil and Citrucel will provide relief from constipation.
Enteric-coated peppermint oil capsules have strong antispasmodic properties and help people with common IBS symptoms like pain, constipation, bloating, and gas. This has been shown in several studies. Using enteric-coated caps ensures that it is not broken down in the stomach but in the intestines, thus preventing heartburn.
Probiotics balance gut flora and impart benefits to IBS patients by slowing down the transit time of the contents of the colon, reducing bowel movements, and improving stool consistency. Probiotics are advised for 12 weeks and if not effective, they can be discontinued.
IBS-specific prescription medications
IBS-specific prescription medications are now available and research is still being made to bring more effective drugs. They are IBS-specific and work specifically on the receptors within the large intestine. They include:
Drugs for constipation-predominant IBS (IBS-C type) include Amitiza (lubiprostone), Constella (linaclotide), and Trulance (plecanatide)
For drugs for diarrhea-predominant IBS (IBS-D type), the American College of Gastroenterologists recommends Viberzi (eluxadoline). This drug is contraindicated in patients with liver disease, gallbladder disease, those who have undergone cholecystectomy, pancreatic disease, and alcoholics.
Antibiotics
There is evidence to show the involvement of unhealthy gut bacteria in IBS-D type (IBS with diarrhea). This provides enough ground for the potential therapeutic benefit of using an antibiotic in the treatment of IBS. Studies have shown that systemic antibiotics eradicate small intestinal bacterial overgrowth and provide symptomatic relief.
These bacteria could be gram-positive or gram-negative thereby raising the need for using broad-spectrum antibiotics with minimal side effects. Several have been effective such as Augmentin, Flagyl, and Norfloxin but when a 2-week regimen is required, these drugs can produce systemic side effects.
Neomycin does offer a good response rate in eradicating unhealthy gut bacteria, but strong evidence has shown that patients develop a clinical résistance to it.
Rifaximin, currently, is the antibiotic of choice used in IBS. It has virtually no systemic absorption (virtually does not get absorbed) and most people using it do not have serious side effects. Even if side effects develop, most of these side effects usually go away within a few days to a couple of weeks. Rifaximin is approved by the Food and Drug Administration (FDA) and is recommended by the American College of Gastroenterology for diarrhea-predominant IBS (IBS-D).
Antispasmodics (Anticholinergics)
Antispasmodics are most frequently prescribed for abdominal pain and cramping in patients with IBS-D. Examples that are commonly prescribed for IBS include Bentyl (dicyclomine) and Levsin (hyoscyamine).
They are most effective when taken 30 to 60 minutes before meals. However, the ACG guidelines do not recommend using them because the studies favoring their use are outdated.
Psychological therapies
The recommendation of psychological treatments doesn’t mean that IBS is a psychological disorder. Rather, psychological therapies help you to cope with your chronic disorder and build better habits.
A therapist can help you get control over your stress and conditions such as anxiety and depression.
IBS-specific cognitive behavioral therapy can be effective for the management of stress-related IBS and can give relief from symptoms.
Gut-directed hypnotherapy has been shown to produce better long-term results than IBS medication with the added advantage of no side effects. In addition, besides improving gut symptoms, IBS hypnotherapy has improved other non-gastroenteritis symptoms, such as insomnia and anxiety.
Neuromodulator drugs should be considered when symptoms have not improved after 12 months of drug treatment. This therapy consists of the use of neuromodulators, also known as antidepressants, antianxiety, or antipsychotic medications. They target pain and motility caused by the dysfunction of the gut-brain pathway. They can also help with visceral anxiety and mental health symptoms. Some examples of neuromodulators used in IBS include Tricyclic antidepressants (TCAs) and Selective serotonin reuptake inhibitors (SSRIs). They can produce a clinical response in 6-8 weeks, but these drugs need long-term treatment (usually 6-12 months) after the initial response to prevent relapse. To discontinue these drugs, they have to be tapered slowly over 4 weeks.
Tricyclic antidepressants (TCAs) are the most favored antidepressants and are also recommended by the ACG. According to new research, published in The Lancet, a low dose of amitriptyline can be an effective treatment for IBS-D type. Amitryptyline is started in a low dose and may be required to be given for several months. Other TCAs used include Doxepin, Norprimin (desipramine), and Surmontil (trimipramine).
Selective serotonin reuptake inhibitors (SSRIs) are prescribed less often. An SSRI may be prescribed to improve abdominal pain and abdominal symptoms such as constipation and anxiety. However, they aren’t recommended by the ACG. They are prescribed in lower doses when treating IBS than when used to treat depression. Examples include fluoxetine (Prozac) or paroxetine (Paxil).
Yoga and meditation.
Some specific yoga exercises modulate your gut and prevent its dysfunction. Meditation will help to relieve stress, which can be a trigger for IBS symptoms. A lot of research and studies give a thumbs-up for the use of both these remedies that have improved symptoms in people with IBS.
