Signs, Symptoms and the Diagnosis of IBS

Before launching into the signs and symptoms of IBS, some definitions and clarifications.

There is a difference between signs and symptoms—signs are objective measures—these are seen by someone other than the person who is ill.  Symptoms, on the other hand, are the subjective sensations felt by the person who is ill—they may (and or course, should) report these symptoms to a physician.  The physician will do a physical examination or order lab tests to determine the objective signs such as blood pressure, increased bowel sounds (indicating increased motility and/or increased gas), increased abdominal distension (indicating gas and bloating—symptoms that the patient may be reporting) or the presence of fecal masses found by palpating (touching and pressing) the abdomen.  Some signs –like a rash—can be a symptom because both the doctor and the patient can observe the rash.  Some symptoms, such as fever can also be a sign.  On the other hand, some symptoms—such as pain or a headache—can’t be a sign because it depends on the patient’s perception and can’t be otherwise objectively measured.  We can use, for example, a Likert scale from 1-10 to describe the level of pain, but that is only partly objective because different people perceive pain differently.

There are four main types of symptoms.  These are:[1]

• Acute symptoms are those that appear suddenly. These may be due to trauma, acute injury or a new disorder or disease such as acute appendicitis, a neck injury from a fall or the chest pain in a heart attack.
• Chronic symptoms are those that are long lasting or are recurrent. These are commonly due to long-term diseases or disorders such as diabetes, high blood pressure or IBS.
• Relapsing symptoms come and go. These relapsing symptoms may come and go quickly or more slowly.  Depression, multiple sclerosis, Lyme disease and some patients with IBS may have relapsing symptoms when, for example, the abdominal pain is relieved by having a bowel movement.
• Remitting symptoms are those that improve, sometimes going away completely. There is a form of relapsing-remitting multiple sclerosis.  IBS can be thought of as having remitting symptoms if, for example, increased fiber along with probiotics relieves the symptoms of abdominal pain and discomfort.

In IBS, you will likely go through an abdominal exam.  The abdomen is thought of as being divided into 4 quadrants—right and left upper quadrants and right and left lower quadrants.  In an abdominal exam, the physician will first listen to the sounds of the abdomen in all four quadrants.  The physician is also likely to perform percussion—this is a light tapping of all four abdominal quadrants—you might notice that there will be different sounds in different areas of the abdomen.  Finally, the physician will palpate—this when the physician will press down on various parts of the abdomen, sometimes pressing lightly and at other times, pressing down more deeply.  All these techniques can result in the various signs described below.  In general, only deep palpation is somewhat uncomfortable, but with IBS, this exam can be quite uncomfortable.  You should feel free to let the physician know what hurts and when it hurts.  For some people, the palpation itself can stimulate diarrhea—you should also feel free to let the physician know this as well.

Signs and Symptoms of IBS

Some physicians divide IBS into three types while others recognize four types of IBS. [2] The commonly recognized types of IBS are:

• IBS with constipation or IBS-C.
  • Symptoms include:
    • Abdominal pain
    • Abdominal discomfort
    • Bloating
    • Difficulty in having a bowel movement
    • Lumpy, hard and/or large stools that are difficult or painful to pass
    • Infrequent bowel movements.
  • Signs of IBS-C include:
    • Abdominal distention (a swelling or ballooning of the abdomen, often referred to by patients as bloating) on palpation.
    • Fecal masses can be felt in the large intestine on palpation.
    • Bowel sounds can be reduced. This is generally determined as the physician listens to the abdomen for the sounds known as “bowel sounds” These are often described as gurgling, bubbling, or shushing sounds and indicate movement of contents through the bowels.
  • IBS with diarrhea or IBS-D
    • Symptoms include:
      • Frequent bowel movements
      • Loose, watery stools
      • Abdominal pain
      • Abdominal discomfort
      • Urgency with bowel movement
    • Signs include:
      • Increased bowel sounds
      • Discomfort on palpation that may result in bowel urgency (a need to use the bathroom)
    • IBS with mixed diarrhea and constipation or IBS-M
      • Signs and symptoms are those of IBS-C or IBS-D, depending on the current form of IBS. In other words, while constipated, you will likely have the signs and symptoms of IBS-C.  While experiencing diarrhea, you will have the signs and symptoms of IBS-D.
    • A form of IBS that is recognized by some physicians, but not all, is IBS that alternates between diarrhea and constipation or IBS-A. [3] IBS-A can be differentiated from IBS-M because of the rapid “flares” switching from diarrhea to constipation and then repeating the cycle with short remission periods. The flares are generally last less than one week as do the remissions. This fluctuation is not due to medications, but is a distinct form of IBS. People with IBS-A also tend to report more psychological problems than those with IBS-C, IBS-D or IBS-M.  In IBS-M, there is less of a distinct pattern of diarrhea or constipation.

The Rome IV Diagnostic Criteria

• Recurrent abdominal pain that occurs (on average) at least 1 day per week for the last 3 months. This recurrent pain must be associated with 2 or more of the following:
  • Related to defecation/bowel movements
  • Associated with a change in how often one experiences a bowel movement (frequency of stool)
  • Associated with a change in form (appearance) of stool (eg. a change in how loose, watery or hard a stool is)
• Symptoms began at least 6 months prior to diagnosis.

Tests and Diagnosis for IBS

IBS is a functional disorder.  Part of what this means is that there is no single test or group of tests that can diagnose IBS.  The criteria needed for diagnosis have been in a process of evolution.  For many years, the Manning criteria were used for diagnosis. Currently, physicians use the Rome III criteria for diagnosis.  Rome IV criteria have been released.[4]  These criteria use the signs and symptoms of IBS but can only be applied if there is no anatomic or biochemical abnormality found. There are a number of other “red flags” that need to be excluded before the Rome IV criteria can be applied.  These include:

• Abnormal blood tests: eg. a normal Complete Blood Count (CBC) or a normal Comprehensive Metabolic (a Comp Metabolic) blood chemistry panel
• No blood in the stool
• Fever
• Unintentional or unexplained weight loss
• Night-time symptoms that wake a person up
• Use of antibiotics in the recent past
• New symptoms in people over 50 years old
• New or different symptoms
• Family history of digestive disorders such as celiac disease, inflammatory bowel disease, diverticulitis or colon cancer or familial polyps.

Other conditions often occur alongside of IBS—these need to be diagnosed and sometimes treated separately.  Some of these conditions include:

• Fibromyalgia
• Hyperacidity or GERD
• Insomnia
• Anxiety
• Depression

While the Rome IV criteria form the core of IBS diagnosis, along with a physical exam, your physician will likely order some tests that are not specific for IBS, but may help either include or exclude other conditions that can affect your IBS.  Some of the likely or possible tests that may be included are:

• Blood tests are routine and would include a CBC and a CompMetabolic test. Your physician may order testing for gluten antibodies (anti-gliadin antibodies) to exclude celiac disease.  Other tests may be to test for inflammation—these may include an ESR (Erythrocyte Sedimentation Rate) or hsCRP (heat sensitive C-reactive protein).  Both these are relatively non-specific markers of inflammation. A new set of tests for IBS-D have not been fully evaluated, but may also be ordered if available—these blood tests test for antibodies to Cdtb (a bacterial toxin) and vinculin (a human protein found on the surface of cells).[5]
• Stool tests. These may be looking for parasites, bacterial infection or for the presence of blood in the stool.
• A lower GI series using barium as a contrast agent may be required. These are often known as barium enemas.  This should not be done in pregnant or possibly pregnant women.  It requires swallowing a barium solution—after giving enough time for the barium to enter the intestines, an X-ray is taken.  This test is being phased out except in special circumstances and is being replaced by either a sigmoidoxcopy or a colonoscopy which is a visual exam using a camera loaded onto a flexible tube. A small sample of intestinal tissue may be taken for microscopic examination.
• Breath tests may be done to test for:
  • Hydrogen gas. This can help to determine:[6]
    • Lactase deficiency (and therefore lactose intolerance)
    • Small Intestinal Bacterial Overgrowth (SIBO)
    • Decreased transit time through the intestines.
  • Lactulose or glucose
    • This breath test can also be used to determine if bacterial overgrowth may be at the root of the symptoms. However, the hydrogen breath test is more commonly used as it appears to be a more accurate test.[7]
  • You may also be asked to take some psychological tests or may be referred to a counselor or psychotherapist for evaluation of your mental state.

Treatment Guidelines for IBS

The American Gastroenterological Association (AGA) has recently published guidelines designed to help your physician made medication choices for treatment of IBS in addition to non-medication choices such as fiber, dietary modification, biofeedback, acupuncture, probiotics or any other non-drug approach to IBS. [8]

The recommendations for IBS-C include:

• A strong recommendation to use linaclotide over no drug-treatment
  • Since the out-of-pocket costs of linaclotide are high, and diarrhea is a common adverse effect of linaclotide, alternative treatments may be recommended
• A conditional recommendation to use lubiprostone over no drug-treatment
  • Since the out-of-pocket costs of lubiprostone are high, alternative treatments may be recommended
• A conditional recommendation to use PEG laxatives over no drug-treatment

The recommendations for IBS-D include:

• A conditional recommendation to use rifaximin over no drug-treatment
• A conditional recommendation to use alosetron over no drug-treatment
• A conditional recommendation to use loperamide over no drug-treatment

The recommendations for all forms of IBS include:

• A conditional recommendation to use tricyclic antidepressant over no drug-treatment for pain relief
• A conditional recommendation NOT to use selective serotonin reuptake inhibitors (SSRIs) over no drug-treatment
• A conditional recommendation to use antispasmotics over no drug-treatment

Strong recommendations indicate that:

• Most people in this situation would want the recommended course of action, and only a small proportion would not. Formal decision aids are not likely to be needed to help patients make decisions consistent with their values and preferences.
• Most patients should receive the recommended course of action. Adherence to this recommendation according to guidelines could be used as a quality criterion or a performance indicator.

Conditional (weak) recommendations indicate that:

• The majority of people in this situation would want the suggested course of action, but many would not. Decision aids are useful in helping patients make decisions consistent with their values and preferences.
• Physicians should examine a summary of the evidence to help patients make a decision that is consistent with their own values and preferences (shared decision making).

References

[1]. http://www.medicalnewstoday.com/articles/161858.php

[2]. http://www.webmd.com/ibs/guide/types-ibs

[3]. http://www.medscape.com/viewarticle/501642

[4]. http://theromefoundation.org/rome-iv/

[5]. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0126438

[6]. http://www.medicinenet.com/hydrogen_breath_test/article.htm

[7]. http://www.ncbi.nlm.nih.gov/pubmed/22472730

[8]. http://www.gastro.org/guidelines/2014/9/14/pharmacological-management-of-ibs