Irritable Bowel Syndrome: Causes, Symptoms and Treatment

IBS symptomIrritable bowel syndrome (IBS) is a condition that you can’t diagnose with conventional diagnosis. It is a condition that is often identified only by the symptoms you’re experiencing. The symptoms you may experience include prolonged abdominal pain or uneasiness associated with rectal evacuation, an uncomfortable feeling of fullness (bloating), symptoms of gas, changes in bowel habits (constipation, diarrhea, or alternating), and features of disordered defecation.

IBS can greatly upset the function of your GI tract. However, unlike ulcerative colitis and Crohn's disease, it doesn't cause any structural abnormalities. For this reason, it does not pose a significant physical danger to your body and does not harm the bowel tissues or increase the risk of developing cancer.

Signs and Symptoms

IBS has no organic cause. It can affect anyone at any age, but women are more likely to have it than men are. It is more common in individuals younger than 45 years.

IBS causes various symptoms, which vary from person to person. Symptoms are most often attributable to the functional problems of the intestines. That means symptoms will result from a problem with how the intestine function or work. Some people with IBS are more severely affected than others. However, only a small number of individuals have severe symptoms.
symptom of IBS

Common symptoms of IBS include:

  • Abdominal pain and cramping in the lower belly, which may be relieved by passing stools (feces) or wind. The pain may come and go in episodes and may worse after eating. In addition, the pain may be linked to a change in bowel movements.
  • Bloating and swelling of the stomach may occur infrequently. Sometimes, a crampy abdominal pain may come with the feeling of abdominal distension. An unusually excessive gas may be passed.
  • Abnormal stool frequency and appearance may occur from time to time. Some people may have bowel movements more often (diarrhea with greater than three pass out per day) than usual, and some may have less often (constipation with less than three defecations per week) than usual. The stool forms may vary in size or consistency. Sometimes the stools may appear less solid and more watery, and sometimes they may be harder, smaller, and lumpier. At times, mucus may also pass with stools.
  • Abnormal bowel movement patterns may also accompany with the above symptoms. Occasionally, people with IBS may feel an urgent need to go to the toilet, or feel that they haven't fully emptied their bowels.


There are no definite tests to diagnose IBS. Doctors often check for specific symptom criteria that are typical for the condition. When they are met, it is considered that IBS is present in the diagnosed person. The criteria include:
  • The patient has had persistent abdominal pain or uneasiness for at least 3 days a month in the last 3 months associated with a change in bowel movements and in stool frequency and appearance.
  • The patient has recurrent bloating, tension or hardness in the stomach.
  • The patient has no other diseases or injuries that could cause same type of symptoms.
  • The patient's overall quality of life is impaired.
In addition, the doctors will take a complete medical history of the patient and may run some tests to exclude the possibility of other diseases. A stool test is often performed to check the evidence of bleeding. Additional testing is not usually required. However, the doctor may include some other tests if certain findings during the evaluation lead to alarming signs of other medical conditions. The doctor may also run other diagnostic procedures such as blood tests, x-rays, and colonoscopy to screen for other problems.

Conventional Treatment

IBS is a chronic condition that needs long-term care. The economic impact of IBS is also significant. Studies suggest that it accounts for high medical costs and indirect expenses, including excessive absenteeism from work/school and increased rates of physician visits. Treatment of IBS includes lifestyle and food style changes, medications, and counseling.

As the causes of irritable bowel syndrome are still unidentified, conventional treatment of IBS usually focuses on the relief of symptoms using medications. These medicines help prevent the primariy IBS symptoms, interfering with a patient's daily activities. These include:

1. Antispasmodics, such as dicyclomine (Bentyl), hyoscyamine (Levsin), and mebeverine (Colofac), help ease colon muscle spasms and relieve abdominal (stomach) pain. However, these medications are often prescribed for IBS patients have bouts of diarrhea, but not for people coping with constipation. Studies suggest antispasmodics may worsen symptoms of constipation and may cause other complications.

2. Antimotility agents, such as diphenoxylate (Lomotil) and loperamide (Imodium), can help relieve diarrhea. Although a number of antimotility medicines are available in the market, but, for IBS, loperamide is the highly recommended of all due to its low side effects. Loperamide works by slowing the bowel movements through the large intestine. This action slackens the frequency of stool passing and allows more time to improve stool consistency.

3. Dietary fiber has long been advised as a remedy for IBS. It is a type of carbohydrate that the body poorly absorbs. It usually remains in the gut, and is excreted from the body as a main part of stools. There are two broad types of fiber: soluble fiber (which dissolves in water) and insoluble fiber (which doesn't dissolve in water).

Both soluble and insoluble fibers are often recommended for patients with constipation-predominant IBS. They prevent constipation by increasing stool frequency and consistency. Studies suggest insoluble fiber enhances water-holding properties of the stools, encourages regular bowel movement, and promotes bulk movement through the intestines, while soluble forms gel to lubricate the bulk.

However, the recommendation has slightly changed over the years, because high-fiber diets can cause gas and bloating, which may exacerbate IBS symptoms. They may also interfere the body’s absorption of several minerals like iron, calcium, and zinc. So, most doctors now advise to take fiber in moderation.
Natural sources of fiber: peas, oats, apples, beans, carrots, wheat bran, corn bran, nuts, lignans, and citrus fruits.
4. Fiber supplements, such as methylcellulose (Citrucel) or psyllium (Metamucil), are potent agents used to clean out the intestinal tract and colon. They help move stools through the intestines and improve bowel movement. These supplements have also been reported to help relieve IBS associated constipation. Physicians often recommend them when increasing dietary fiber is unsuccessful.

5. Osmotic laxatives, such as lactulose, polyethylene glycol, or milk of magnesia, may be prescribed if fiber supplements don't help lessen constipation associated with IBS symptoms. Laxatives work in different ways. They make the stools softer by increasing intestinal fluid, so that stools can pass out more easily. However, it is reported that laxatives may cause an obstruction in the GI tract. Therefore, people with IBS-related constipation should consume plenty of fluids while taking an osmotic laxative.

6. Antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs), have been reported to relieve stomach pain and cramping with low doses. Although a higher incidence of psychological disorders, such as depression and anxiety, is often found in people with IBS, but these medications can be used in IBS patients without mental illnesses, as they can provide pharmacological effects independent of any antidepressant effect. Antidepressants are often prescribed if persistent IBS symptoms have not been relieved by other medications.

Low doses of TCAs, such as imipramine and amitriptyline, have shown to work best when abdominal pain and diarrhea are the main symptoms. However, TCAs are not advised for IBS patients who have bouts of constipation, because they may worsen constipation. SSRIs, such as fluoxetine and paroxetine, are occasionally used for IBS. They can help reduce pain and bloating sensations as well as facilitate intestinal transport and secretions. Studies suggest SSRIs are better for patients with IBS associated constipation and depression.

7. Rifaximin, a semisynthetic antibiotic derived from rifamycin, is occasionally prescribed for IBS patients to eliminate intestinal bacteria and reduce abdominal bloating. This drug is used in IBS treatment because of its poor oral bioavailability. After oral intake, only a little of the drug is absorbed into the blood and most of the drug stays in the gut. Experts believe rifaximin may help relieve symptoms of diarrhea in an IBS patient if there is an overgrowth of bacteria in the intestine.