40 Fun Facts About Irritable Bowel Syndrome

Which over-the-counter drug for IBS with diarrhea, sold as Imodium, is technically an opioid?

Loperamide acts on opioid receptors in the gut wall but does not cross into the brain at normal doses, so it slows the bowel without a high.

About 90% of which chemical messenger, a target of several IBS drugs, is made in the gut?

Serotonin is mostly made by cells in the gut lining, where it regulates the movement of the bowel rather than mood.

Which herb's oil, taken in coated capsules, beat a placebo at easing IBS symptoms?

Peppermint oil capsules are coated to pass through the stomach intact, because chewing or breaking one can bring on acid reflux.

People with IBS are about three times more likely to have surgery on which organ, often needlessly?

Gallbladder removal is more common in IBS because the cramps get blamed on gallstones the person happens to have.

In the Western world, irritable bowel syndrome is about twice as common in which group of people?

Women in Western countries are diagnosed about twice as often as men, yet studies in East Asia find no such gap between the sexes.

Which illness raises the risk of IBS about six-fold, causing the post-infectious form?

Gastroenteritis triggers roughly one in ten cases of IBS, and a prolonged fever during the infection pushes the risk higher still.

Which network of neurons in the gut wall, studied in IBS, is nicknamed the second brain?

Enteric nervous system neurons number about 500 million, and they keep the gut working even when the main nerve link to the brain is cut.

Doctors diagnose IBS with symptom criteria named after which European capital city?

Rome lends its name to the criteria, but the foundation that writes and updates them is based in Raleigh, North Carolina.

The stool form chart doctors use to sort IBS into subtypes is named after which English city?

Bristol Royal Infirmary doctors devised the chart, which sorts stools into seven types from hard lumps to entirely liquid.

Researchers at which Melbourne institution developed the low-FODMAP diet used for IBS?

Monash University researchers also lab-test everyday foods for their FODMAP content and publish the results in a phone app.

Which symptom must be present, alongside changed bowel habits, for a doctor to diagnose IBS?

Abdominal pain is the one symptom the checklist insists on, typically at least once a week over the last three months.

Because IBS leaves no visible damage in the gut, doctors class it as which kind of disorder?

Functional gut disorders have a newer official name, disorders of gut-brain interaction, because the problem lies in how the two work together.

Which condition joins ulcerative colitis as a main type of IBD, an illness often mistaken for IBS?

Crohn's disease inflames the gut wall, which is the key difference: IBS produces similar symptoms but no inflammation of that kind.

Guidelines say everyone with IBS symptoms should be tested for which autoimmune condition?

Celiac disease can pass for IBS, and a low-FODMAP diet may hide it, because cutting back on wheat eases the symptoms without a diagnosis.

Breath tests that rule out IBS look-alikes measure which gas, made in the body only by bacteria?

Hydrogen in the breath after a sugary test drink shows the sugar was not absorbed and reached gut microbes instead.

In the past, doctors called IBS mucous colitis and which other name?

Spastic colon was one of several old labels, and another, plain colitis, was misleading because IBS leaves no visible sign of damage or disease.

IBS subtypes include IBS-C and IBS-D, so what does the M in IBS-M stand for?

Mixed bowel habits means that, on days with an abnormal bowel movement, more than a quarter of stools are hard and more than a quarter are loose.

Which breakfast grain does Britain's NHS suggest eating regularly to ease IBS bloating and cramps?

Oats supply soluble fiber, the kind that helps IBS, whereas the insoluble fiber in wheat bran can make symptoms worse.

Which sweetener, common in sugar-free gum, does Britain's NHS tell people with IBS to avoid?

Sorbitol is a sugar alcohol that the gut absorbs poorly, and the advice to avoid it covers both bloating and diarrhea.

Which therapy is offered in a gut-directed form as a mental health treatment for IBS, alongside CBT?

Hypnotherapy uses a relaxed, trance-like state, and there is some evidence that the gut-directed kind eases IBS symptoms and improves quality of life.

Which barely absorbed antibiotic, used mainly for travelers' diarrhea, is also prescribed for IBS?

Rifaximin stays in the gut instead of entering the bloodstream, and it may ease IBS by resetting the mix of bacteria living there.

Which drug for IBS with constipation is sold as Constella in many countries outside the US?

Linaclotide, sold as Linzess in the US, mimics peptides the gut makes for itself and stays in the digestive tract after it is swallowed.

Which IBS drug, sold as Lotronex, was withdrawn within a year and later returned with restrictions?

Alosetron was pulled after reports of life-threatening bowel complications, then came back when patient groups lobbied for its return.

Which fiber supplement, made from the seed husks of Plantago plants, can improve IBS symptoms?

Psyllium is the active ingredient in Metamucil, and its soluble fiber both firms up loose stools and softens hard ones.

Which older antidepressant is prescribed at low doses for IBS, even to people who are not depressed?

Amitriptyline belongs to the tricyclic group, which helps about one in three people with IBS at doses too low to treat depression.

Which cranial nerve, key to the gut-brain axis in IBS, carries reports from the bowel to the brain?

Vagus traffic runs in both directions, and gut microbes release molecules that can activate the nerve directly.

Which supplements does Britain's NHS suggest people with IBS try for a month?

Probiotics are live microorganisms, most often bacteria, similar to the ones that normally live in the digestive tract.

Which FODMAP carbohydrates, a problem for many people with IBS, are found in wheat, onions and garlic?

Fructans, rather than gluten, are a suspected cause of the gut symptoms that some people blame on bread and pasta.

Which disaccharide makes regular milk a high-FODMAP food while hard cheese stays on the low-FODMAP list?

Lactose need not be cut by everyone on the diet, since many people who benefit from going low-FODMAP do not need to restrict it.

Which professional may an NHS GP refer someone to when general lifestyle changes have not helped their IBS?

Dietitian supervision matters on a low-FODMAP plan because its strict phase is meant to last no more than about six weeks.

Which stool protein is usually normal in IBS but raised in inflammatory bowel disease?

Calprotectin makes up as much as 60% of the soluble protein inside neutrophils, the white blood cells that flood an inflamed bowel.

What is the medical term for the feeling of incomplete emptying after a bowel movement, seen in IBS?

Tenesmus describes a sensation, not a fact, because the feeling of leftover stool often arises when the rectum is actually empty.

Which often-missed condition, found in about 30% of diarrhea-type IBS, responds to sequestrant drugs?

Bile acid malabsorption is often mislabelled as IBS, yet in pooled studies about 80% of those who tested positive improved on cholestyramine.

Which pharmacy remedy for IBS cramps, named by the NHS, is made from a nightshade plant compound?

Buscopan contains hyoscine butylbromide, which is manufactured from a substance found in deadly nightshade and its relatives.

Which alternative therapy did no better than a sham version at easing IBS in a Cochrane review?

Acupuncture was tested against sham needling that does not pierce the skin or misses the proper points, and pooled trials found no gap.

A deficiency of which nutrient, involved in regulating immunity, is more common in people with IBS?

Vitamin D supplements are advised for people with IBS who run low, though not yet as a treatment for the condition itself.

IBS affects about half of people with which muscle and joint condition, hinting at a shared cause?

Fibromyalgia overlaps with IBS so often that researchers suspect a common fault in the body's stress response.

Bacterial overgrowth in which normally sparsely populated part of the gut is linked to IBS?

Small intestine contents normally hold fewer than 100,000 organisms per milliliter, a tiny count beside the bacteria-rich large bowel.

Britain's NHS tells people with IBS to have no more than three cups a day of drinks containing what?

Caffeine sits on the NHS list of IBS triggers alongside alcohol, stress and spicy or fatty food.

Which symptom is a red flag that IBS does not explain and that calls for further tests?

Weight loss joins rectal bleeding and anemia on the list of signs that usually point to something other than IBS.