What causes irritable bowel syndrome?
Researchers remain unsure about the cause or causes of IBS. The digestion and propulsion of nutrients and fluids through the gastrointestinal system (GI) is a very complicated and very well organized process. The GI tract has its own intrinsic muscles and nerves that connect, like an electrical circuit, to the spinal cord and brain. Neuromuscular events occurring in the GI tract is relayed to the brain through neural connections, and the response of the brain is also relayed back to the
gastrointestinal tract. As a result of this activity, motility and sensation in the bowel is generated. An abnormality in this process results in a disordered propulsion of the intestinal contents, which generates the sensation of pain.
It is called a functional disorder because it is thought to result from changes in the activity of the major part of the large intestine (the colon). After food is digested by the stomach and small intestine, the undigested material passes in liquid form into the colon, which absorbs water and salts. This process may take several days. In a healthy person the colon is quiet during most of that period except after meals, when its muscles contract in a series of wavelike movements called peristalsis. Peristalsis helps absorption by bringing the undigested material into contact with the colon wall. It also pushes undigested material that has been converted into solid or semisolid feces toward the rectum, where it remains until defecation. In IBS, however, the normal rhythm and intensity of peristalsis is disrupted. Sometimes there is too little peristalsis, which can slow the passage of undigested material through the colon and cause constipation. Sometimes there is too much, which has the opposite effect and causes diarrhea.
About 25% of patients develop symptoms after a hefty enteritis (partially after use of antibiotics, see also diarrhea). In these cases, a prolonged immune reaction is currently discussed as pathogenetic. So far, this is mainly based on experiments in the animal model. IBS is widely regarded as a conglomeration of disorders with similar symptoms but a different etiology ("trash can"). As with many other medical conditions, there is a lot of speculation about causes, including in the field of alternative medicine. About 10 to 20 per cent of people will date the start of their symptoms to an acute gastroenteritis. In the remainder of cases, the trigger factor remains unidentified. Abnormalities in peristalsis can often be seen in close relatives of people with IBS, although without symptoms. This suggests a trigger sets off the condition in susceptible people. Nerve-signalling chemicals, particularly serotonin, appear to have an important role.
More information on irritable bowel syndrome (IBS)
What is irritable bowel syndrome (IBS)? - Irritable bowel syndrome (IBS) is a intestinal condition characterized by abdominal pain and cramps, changes in bowel movements, gassiness, bloating, nausea, and other symptoms.
What causes irritable bowel syndrome? - An abnormality in digestion and propulsion process cause irritable bowel syndrome. Nerve-signalling chemicals, particularly serotonin, and stress appear to have an important role.
What're the risk factors for irritable bowel syndrome? - Stress stimulates colonic spasm in people with IBS. Female reproductive hormones are another trigger of irritable bowel syndrome.
What are the symptoms of IBS? - Symptoms of irritable bowel syndrome are abdominal pain or discomfort associated with changes in bowel habits in the absence of any structural abnormality.
How is irritable bowel syndrome diagnosed? - Irritable bowel syndrome (IBS) is diagnosed with colonoscopy, esophagogastroduodenoscopy (EGD), abdominal ultrasound, blood tests.
What's the treatment for irritable bowel syndrome? - Treatment of irritable bowel syndrome can consist of dietary advice, stool softeners and laxatives in obstipation-predominant, and antidiarrheals (loperamide) in diarrhea-predominant IBS.
What irritable bowel syndrome diet is suggested? - Fiber supplementation may improve symptoms of constipation and diarrhea. Avoid food or beverages that make the symptoms worse.
What medications cure irritable bowel syndrome? - Antispasmodic medicines are used to treat symptoms of irritable bowel syndrome. Antidiarrheal medications are used when diarrhea is a major feature of IBS.
Stress management for irritable bowel syndrome - Situations such as family problems, work stress, exams, etc, may trigger symptoms of irritable bowel syndrome (IBS) in some people.