The term irritable bowel syndrome (IBS) is relatively modern, but people have had similar symptoms for millennia. Initially thought to exist only in the mind, the disorder has gained legitimacy through the identification of causes and improved diagnosis. By Amber Dance.
Thoth's beak 3500–2500 BC
The ancient Egyptian ibis-headed god Thoth (pictured) was associated with the enema — ibises were thought to self-administer using their long beaks. The Egyptians had specialized physicians to treat abdominal problems.
Mind and body 460–322 BC
Medical science can be traced back to Hippocrates in ancient Greece. He and his contemporaries — Plato and Aristotle — develop the concept of holism: the mind and body are one, and medicine should treat both. For example, Hippocrates not only recommends physical treatments such as enemas (pictured), but also soul-enriching activities such as listening to music. Dysentery, which is now recognized as a trigger of IBS, was then thought to result from an overabundance of blood.
French philosopher René Descartes proposes the theory of dualism: the spirit and body are distinct entities. Because the spirit is no longer thought to inhabit the body, autopsies become more acceptable. Physicians uncover the pathological roots of many conditions and begin to develop treatments. But superstition is not banished altogether. Conditions with no identifiable pathology, including mental-health disorders such as schizophrenia, are blamed on possession and, later, insanity.
Several physicians publish accounts of bowel complaints with names such as membranous enteritis and colitis. “The bowels are at one time constipated, at another lax, in the same person. How the disease has two such different symptoms I do not profess to explain,” writes William Cumming in the London Medical Gazette, adding, “The mental phenomena consequent on it amount, in some cases, to absolute insanity.” Treatments included dietary changes, opiates, mustard poultices and electrotherapy.
American psychologist William James proposes a direct link between emotions and the body. For example, the theory suggests that the feeling perceived as anxiety results from the sensation of butterflies in the stomach.
Abominable abdominals 1920s
Some physicians apply derogatory terms to people who repeatedly seek help for digestive symptoms. In his lectures on dyspepsia, British physician Robert Hutchison complains of the “incessant” demands of the “abdominal woman”.
Mould breaking 1928
British biologist Alexander Fleming discovers a mould that kills bacteria, leading to the development of penicillin and other antimicrobials. These drugs will help to tame the cause of dysentery.
The Second World War is over, but not the intestinal troubles of many soldiers and sailors who contracted dysentery in the tropics. Their symptoms continue or recur even after the causative microbes have gone. Writing in the British Medical Journal, G. T. Stewart suggests that long-term changes to intestinal flora might contribute to lingering diarrhoea.
Presidential problems 1961
During his time in office, then US president John F. Kennedy suffers from severe diarrhoea — as he did for much of his life. Doctors diagnose spastic colitis, which would now be called IBS.
Road to Rome 1962
Nazir Chaudhary and Sidney Truelove describe what they refer to as irritable colon syndrome. To their patients, the pair call the problem misbehaviour of the bowel and treat it with the sedative phenobarbital and the muscle relaxant propantheline bromide. Patients also report psychological symptoms such as anxiety or depression. Over the decade, the term irritable bowel syndrome becomes more popular.
The first drug marketed specifically for IBS in Europe is the anti-spasmodic mebeverine, which relaxes the gut muscles.
Tummy bug 1984
Australian physician Barry Marshall drinks Helicobacter pylori to prove that the bacterium causes gastritis and ulcers, disproving the long-held view that these conditions have a purely psychological origin.
Gastroenterologists gather in Rome to draft guidelines for the diagnosis of IBS, helping to legitimize the condition. The criteria generate some controversy: they do not perfectly distinguish IBS from other similar conditions, and they are difficult to validate. But use of these guidelines grows in clinics, research and drug trials, and grant agencies insist on their use (see page S107).
Strength in numbers 1987
The patient organization the IBS Self Help and Support Group is formed in the United States. It now has around 60,000 members.
Dualism debunked 1988
The idea that IBS can result from interactions between the brain and the gut emerges from a survey reporting that certain psychological conditions typically make the syndrome worse, and lead people to seek medical attention (D. Drossman et al. Gastroenterology 95, 701–708; 1988).
In February, the US Food and Drug Administration (FDA) approves the serotonin-receptor blocker alosetron for women with diarrhoea-predominant IBS. By November it has been withdrawn. Several patients have had complications due to constipation, such as a ruptured bowel, and some have died. Under public pressure, the FDA allows its use again in 2002, but only for women with severe diarrhoea.
Researchers describe the first evidence of a specific molecular defect that may be a cause of IBS. The guts of people with IBS, as well as those with ulcerative colitis, contain relatively low amounts of both serotonin and an enzyme that synthesizes it, as well as a transporter that brings serotonin into cells (M. D. Coates et al. Gastroenterology 126, 1657–1664; 2004). Although this result is initially controversial, later studies confirm it.
Heart hurts 2007
Pharmaceutical company Novartis withdraws tegaserod, a drug for constipation-predominant IBS, after reports that it can cause severe cardiac problems in some people.
Bacterial bounty 2008
Evidence emerges that the low-FODMAP diet, which omits foods containing short-chain carbohydrates, can improve symptoms in people with IBS (S. J. Shepherd et al. Clin. Gastroenterol. Hepatol. 6, 765–771; 2008). It is a very restrictive diet, but, because it seems to help up to two-thirds of people, it is increasingly adopted, often without medical advice (see page S108).
Faecal analysis reveals that people with IBS have an altered gut microbiome, including more representatives of the phylum Firmicutes and fewer of Bacteroidetes (see page S104). This discovery opens up possibilities for diagnostic tests and treatments. Later, children with IBS who have certain microbes in their gut are found to be more likely to benefit from the low-FODMAP diet.
In the genes 2014
About 2% of people with IBS carry mutations that cripple the SCN5A gene, which is known to encode a sodium channel that acts as a pacemaker for contractions in both the gastrointestinal tract and the heart (A. Beyder et al. Gastroenterology 146, 1659–1668; 2014).
The stigma surrounding IBS continues to fade. During the Super Bowl, football fans are shown an advertisement for the drug rifaximin, featuring an animated intestine. Celebrities such as supermodel Tyra Banks (pictured) have previously spoken about their digestive symptoms. But despite the recent approval of several medications, scientists have much more to do to untangle the disparate causes of IBS.
This article is part of the Nature Outlook: IBS