Diagnosis of IBS
Digestion
Our last blog described the digestive system. We will now consider what takes place in this digestive process. It is a continuous changing of substances, which is brought about chemically and organically. This changing is called Metabolism. Upon food being taken into the stomach, it is then mixed with gastric juice and passed into the small intestine in a semi digested state called chyme. At the entrance of the duodenum is the pyloric sphincter muscle, a constricting ring which prevents chyme passing through until it is of the right consistency. This process takes about three hours.
As food passes through the duodenum, it receives bile, (manufactured by the liver), from the gall-bladder, and pancreatic juices from the pancreas. The ducts from each gland unite so that the two secretions are poured into the duodenum at the same time and place, - about three inches from the pyloric orifice.
In the small intestine, much of the changed food element is absorbed into the bloodstream. All the digested food is dealt with here, the undigested parts passing on into the large colon, where liquid food is absorbed. Any remaining undigested parts are then pressed forward by peristalsis action until they reach the sigmoid flexure, and are ejected into the rectal tube.
The intestines ARE NOT BOWELS, as popularly understood, - they are digestive organs. The bowel commences where the small tube leads from the sigmoid flexure. It consists of this tube, (about 2” long), and the rectum. The bowel has one function only, that of dealing with the faeces.
Food passes into the large intestine two to five and a half hours after eating, but it requires nine hours or more before a complete meal has been dealt with.
Diagnosis of IBS
Until recently IBS was usually diagnosed by exclusion of diagnosable physical abnormalities and organic disease. In other words various tests, x-rays and examinations would be made in order to rule out other digestive problems such as chrohn’s, colitis and bowel cancer etc. A diagnosis of IBS could take a very long time which meant a long period of uncertainty and consequent worry and lots of invasive diagnostic ‘tools’ being inserted into the body. This period of worry and stress would often exacerbate the symptoms.
In February 2008 the National Institute for Health and Clinical Excellence (NICE) issued new guidelines to the NHS for the diagnosis and management of IBS in primary care. http://www.nice.org.uk/nicemedia/pdf/cg61ibsqrg.pdf
NICE say that “Key elements of management are establishing a positive diagnosis; identifying symptoms that require prompt referral, and working in a long term partnership with the person with IBS, which is a significant change form the previous practice of diagnosing, predominantly by exclusion of diseases, which often led to unnecessary investigations and referrals.”
IBS can be diagnosed if someone reports having had any of the following symptoms for at least 6 months:-
Abdominal pain
Bloating
Change in Bowel habit
And if abdominal pain or discomfort is relieved by defecation or associated with altered bowel frequency or stool form and at least 2 of the following apply;-
Altered stool passage (straining, urgency, incomplete evacuation)
Abdominal bloating, distension, tension or hardness
Symptoms made worse by eating
Passage of mucus
Symptoms of lethargy, nausea, backache and bladder symptoms maybe used to support a diagnosis. However, many of these symptoms can overlap with other gastrointestinal disorders.
NICE recommend that treatment and care should take into account patients individual needs and preferences and that good communication is essential to allow patients to reach informed decisions about their care.
Once the diagnosis has been made the patient and their family or carers will be given the opportunity to be involved in decisions about treatment and care. General dietary and lifestyle advice including physical activity levels and relaxation will be provided and a referral to a dietician made if diet is considered to be a major factor. For people who don’t respond to dietary and lifestyle changes or to pharmacological treatments after 12 months, a referral for psychological interventions will be considered such Hypnotherapy, CBT or other psychological therapy.
In our next blog we look at how and why IBS might have a psychological component to its symptoms.
