What Is Irritable Bowel Syndrome?

Irritable bowel is a gastrointestinal disorder suffered by more than 10% of the population. In this article we inform you of the most relevant aspects of this syndrome.
What Is Irritable Bowel Syndrome?

Last update: 07 April, 2023

Irritable bowel syndrome is a chronic, functional gastrointestinal disorder that appears on a recurring basis. The symptoms are quite nonspecific but are usually characterized by abdominal pain and/or discomfort. In addition, it’s usually accompanied by episodes of diarrhea or constipation.

Common causes of irritable bowel syndrome

It’s normally produced by hypersensitivity or alteration of gastrointestinal motility. Sometimes it can be due to a previous bacterial infection.

It’s believed that there may also be a genetic factor, as well as the action of serotonin, which acts both at the intestinal and neuronal levels. Serotonin plays a fundamental role in the regulation of gastrointestinal motility, as well as in its secretion and sensitivity function.

Who usually gets irritable bowel syndrome?

It’s one of the most frequent syndromes, affecting more than 10% of the population. Irritable bowel syndrome is more common in women than in men, with three women being affected for every one man.

It usually appears between the ages of 15 and 65, but is diagnosed especially after the age of 30. It’s related to family history, but experts don’t know how the genetic factor influences it.

It doesn’t seem to be related to an increase in the development of cancer or an increase in mortality, but it involves a large number of medical visits, incurring considerable health costs.

Irritable bowel syndrome.

IBS symptoms

The symptoms of irritable bowel syndrome are quite nonspecific and, therefore, the diagnosis is usually made by ruling out other conditions. The main symptoms are gastrointestinal in nature, but others related to different parts of our body also appear.

Most frequent symptoms

  • The most frequent symptoms of irritable bowel are abdominal discomfort or pain, which isn’t easy to differentiate from other pathologies. It can be mild or moderate.
  • Usually, this pain is accompanied by episodes of diarrhea (more than 3 bowel movements a day) or constipation (less than three bowel movements a week). Pain is usually relieved by going to the toilet.
  • Although defecation softens the pain, it can lead to other discomforts such as the sensation of incomplete evacuation or the presence of mucus stools.
  • Dyspepsia, distension or swelling, burning and/or regurgitation are other symptoms.
  • Urinary problems
  • Sexual dysfunction, as well as pain during or after sexual intercourse
  • Fibromyalgia
  • Alterations in menstruation
  • Lumbar pain
  • Headaches
  • Sleep disturbances and insomnia

All these symptoms can cause psychological alterations such as depression, anxiety, and somatization.

In general, different types of irritable bowel can be differentiated, depending on the pattern they follow. It’s common for patients to switch between one type or another:

  • With diarrhea
  • With constipation
  • Mixed bowel habits or cyclical patterns
Diarrhea adverse effects.


Currently, there’s no treatment capable of alleviating all the manifestations of irritable bowel syndrome. Most patients with irritable bowel have mild symptoms. In these cases, pharmacological treatment isn’t usually used, and dietary recommendations are of great help.

In addition, exacerbations of pain are often associated with certain foods, as well as drinking alcohol, and periods of stress. Therefore, it’s important to pay attention to these factors, and it’s essential to have a good doctor-patient relationship.

Diet as treatment

Control of the patient’s diet is often considered the first-line treatment for a patient with irritable bowel syndrome. A diet rich in soluble fibers, such as ispaghula, relieves symptoms. Additionally, it appears that some probiotics can also generally improve irritable bowel syndrome symptoms.


Irritable bowel syndrome has very varied and nonspecific symptoms. That’s why there’s no single treatment, but, rather, different options oriented to the various symptoms.

Available treatments:

  • Antispasmodics for short-term pain relief – Typically used as first-line treatment.
  • Laxatives, fiber, and bulking agents to improve symptoms associated with irritable bowel with predominant constipation.
  • Antidiarrheals, fiber, and bulking agents, for forms of irritable bowel where diarrhea predominates.
  • Tricyclic antidepressants: These are usually effective, but have adverse effects, such as drowsiness or sedation. Some examples are amitriptyline or desipramine.
  • Serotonergic agonists, such as paroxetine or citalopram, appear to be effective, but their chronic use isn’t recommended.
  • Other medications: for example, paracetamol as a pain reliever. Ondansetron appears to relieve urgency, bloating, and diarrhea.

In short, there’s no single treatment that can alleviate all the symptoms associated with irritable bowel syndrome. There are different drugs indicated for different symptoms, but the primary treatment of choice is usually based on dietary recommendations. It’s important to personalize the treatment and adjust it to each patient and each situation.

  • Fried, M., Kok-Ann, S., Singapur, G., Khalif, I., Pali, R., Reino, H., … Bajos, M. P. (2015). Directrices Mundiales de la Organización Mundial de Gastroenterología Síndrome de Intestino Irritable: una Perspectiva Mundial.
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