Irritable bowel syndrome (IBS) is a common long-term recurrent functional gastrointestinal disease that causes persistent abdominal discomfort or pain and bowel disturbances (constipation or diarrhea). IBS has other common names, such as spastic or nervous colon, spastic bowel, and mucous colitis. IBS doesn’t cause severe or life-threatening complications; it also doesn’t increase the risk of other gastrointestinal problems, such as ulcerative colitic or colon cancer. But, it is a very frustrating problem that has a significant impact on the quality of life. Patients with IBS often miss work or school and often need to modify their life and work settings to adapt to this chronic condition. Also, anxiety and depression are common among these patients.
IBS affects about 10-20% of the population. It is common in females. It usually occurs before the age of 45 and becomes less common with age.
IBS symptoms vary from one patient to another, but the most common symptoms are abdominal pain, cramps, constipation, diarrhea, bloating, and urgency to defecate. IBS occurs in flares that usually last for several days then improve or resolve. With gastrointestinal problems, IBS patients may experience sexual or urinary problems. Women may have more symptoms around menstruation time.
The exact causes of irritable bowel syndrome are unknown. Theories suggest that the colon becomes hypersensitive to mild stimuli, its muscles become spastic, or its movement becomes slow. Other theories suggest that there are disturbances in the body’s chemicals, such as serotonin. Small studies suggested that food poisoning and intestinal infections may be a cause. While the exact cause is unknown, we know several triggers that may be the key to management by avoiding them. These triggers include gastrointestinal infections, psychological stress, and food allergy. Also, there are risk factors, such as young age, female, sex, positive family history, anxiety, and depression.
IBS doesn’t have specific laboratory tests or investigations that can diagnose it. The diagnosis depends on the symptoms and exclusion of other serious diseases that may have similar symptoms. The doctor should exclude any worrying features, such as old age, weight loss, rectal bleeding, and anemia. These features may be a red flag for other serious diseases, such as colon cancer, ulcerative colitis, chron disease, coeliac disease, and food intolerance. The investigations depend on what the doctor wants to exclude and may include blood tests, stool examination, abdominal ultrasound, or endoscopy.
The criteria to diagnose IBS (Rome IV criteria) include abdominal pain -for at least one day per week in at least three months-, with two other pain features from the following: