An Overview of Irritable Bowel Syndrome (IBS)

IBS affects 10-20% of the population and is considered a functional gastrointestinal (GI) disorder with symptoms of abdominal pain and excessive or infrequent bowel habits.¹ IBS is differentiated from IBD or inflammatory bowel disease (Crohn’s and Ulcerative Colitis) in that there is no underlying inflammation, physical defects such as ulcers or rectal bleeding, or scarring.

IBS which appears in adolescence or early adult years tends to wax and wane, is related to stress that causes additional emotional distress, does not cause weight loss, fever, or rectal bleeding, and does not occur at night. In those cases, an alternative diagnosis must be sought.

Signs and symptoms of IBS

1. Altered bowel habits such as constipation with hard stools of narrow caliber, pain with bowel movements, infrequent bowel movements and poor response to laxatives. Diarrhea with frequent and loose stools associated with urgency after meals are additional findings.
2. The abdominal pain can be diffuse and located in the left lower abdomen, sharp or dull. Meals initiate the pain and defecation relieves the pain.
3. Abdominal bloating and distension are common features, especially in women, but not required for diagnosis.

Additional symptoms consistent with irritable bowel syndrome in females and males are as follows:

• Clear or white mucus with bowel movements
• Indigestion or heartburn
• Nausea and vomiting
• Sexual dysfunction (including pain with sex or poor libido)
• Urinary frequency and urgency
• Fibromyalgia or diffuse muscle pain
• Stress-related symptoms

Classifications of IBS

Ultimately, there are four classification categories for IBS based on the Rome IV Criteria:

IBS-C

Where constipation is the primary symptom

IBS-D

With predominant diarrhea

IBS-M

With both symptoms of diarrhea and constipation

IBS-U

For those that are not in any of the above categories

Mucus production and abdominal bloating are additional features of IBS, but not diagnostic of any particular sub-type. People in one category can change their subtype if their symptoms change over time.

How do you know if you have IBS?

IBS is often a diagnosis of exclusion, meaning that other gastrointestinal disturbances must be ruled out, especially if the symptoms persist beyond a couple of weeks. Most diarrhea and constipation will improve within days so a trip to your doctor is mandated if it continues for weeks.If you have fevers, bloody diarrhea, an inability to keep clear liquids down, nausea, vomiting, or severe abdominal pain, you should see a doctor immediately.

IBS symptoms in women

For a detailed review of symptoms specific for women and their causes, please see Irritable Bowel Syndrome (IBS) Symptoms in Women Aggravated by Hormones. Below is a summary:

The symptoms of IBS in women can be aggravated or made worse depending on the age and menstrual status. The onset of menarche – the first menstrual period – is the result of the pituitary gland and the hypothalamus, two organs in the brain, secreting hormones that trigger the ovaries to produce estrogen (E) and progesterone (P).

Both hormones are necessary for fertility and menstruation, in the case of a lack of fertilization. Progesterone causes slower gut transit time.² Progesterone levels peak at the time of egg release (ovulation), when constipation is more likely. Conversely, when both progesterone and estrogen levels drop prior to the onset of menses, crampy diarrhea may result, and be aggravated by the prostaglandin release during menstruation. Often, the cramps of menstruation, from prostaglandin release, can mimic the cramps before bowel movements or trigger the loose bowel movements themselves.

In women, endometriosis is often confused with IBS and women with endometriosis are more prone to IBS during flares. Endometriosis is a poorly understood disease that results when menstrual blood or the uterine lining implants on structures outside of the uterus resulting in pain, scarring, and infertility.

Pregnancy is a time of increased IBS symptoms in women due to high and sustained levels of progesterone and estrogen throughout all trimesters. The gallbladder is also affected, which further delays the digestive process. Because fluid demands increase by over 50%, dehydration can contribute to constipation symptoms.

More

IBS symptoms in males

Men in Western cultures are less likely to report IBS symptoms to their healthcare provider, which may explain why less is known about IBS symptoms specific to men. Furthermore, abdominal distension is a more common symptom in women, which means that the old criteria to diagnose IBS in men would have excluded them from the diagnosis if they lacked the symptom of distention

Newer diagnostic criteria like Rome III and IV are intended to be gender neutral. Men and women may experience identical intestinal disturbances. Like women, men with IBS may experience sexual intimacy problems, work-related absences, home, and social dysfunction. They are more likely to experience depression due to the symptoms of IBS.

IBS blood in stool

Can IBS cause blood in stool? Blood in the stool or on your toilet paper after bowel movements can occur in IBS but is likely related to constipation-induced hemorrhoids or small tears, called fissures, from hard stools and straining.

For many, the best way to avoid rectal bleeding is to avoid spicy foods, alcohol, and frequent meat ingestion, while increasing fiber intake with beans, legumes, and vegetables that provide roughage. Other solutions are to increase hydration and magnesium intake, since most people are magnesium deficient and rarely drink enough water.

IBS pain

The pain associated with IBS can be localized to one area or be more diffuse. Discomfort can be sharp, dull, or crampy or a combination that changes from day to day. IBS used to be called ‘spastic colon’ or ‘spastic colitis,’ indicating that the muscles of the bowel twitch or spasm in response to certain triggers. The pain can start after meals and increase right before having a bowel movement. It is often relieved by bowel movements, although the actual bowel movement can temporarily increase the pain.

The mechanism that causes the pain is thought to be due to the spastic muscle contractions of the GI tract. When gas or solid contents move through the colon, the distension pushes the walls outward and this stretches the nerves of the GI tract, sending pain signals to the brain. Some nervous systems are more sensitive to the normal transit of digested food, which may be reflected in the type of food ingested.
IBS cramping usually precedes bowel movements, but can occur during one, especially with diarrhea.

IBS and back pain

Irritable bowel syndrome can be felt as back pain because the nerves that supply the colon arise from the spinal nerves that also supply the back muscles. When the nerves are triggered from the colon as a result of bloating, cramping, gas, constipation, and diarrhea, they send signals back to the spinal cord and brain that can confuse the person as to where the pain arose in the first place. This is called referred pain, similar to the jaw or left arm pain experienced when someone is having a heart attack.

IBS treatment

Dietary changes are the mainstay of treatment strategies. These therapies and this involves limiting sugars found in dairy such as lactose, gluten, sorbitol, fructans, hydrolases, and raffinose. These sugars are known as FODMAPs that stands for fermentable, oligosaccharides, disaccharides, monosaccharides, and polyols.

FODMAPs tend to be poorly absorbed and can lead to the bowel drawing extra fluid into the digested contents which raises the risk of diarrhea.³

Read more on the FODMAP diet.

Foods to avoid with IBS

Milk and lactose

Up to 70 percent of adults worldwide don’t produce large quantities of lactase, an enzyme that breaks down the sugar lactose in milk, according to Johns Hopkins Medicine.⁴

This means that milk and other dairy products can cause gas and bloating, since the lactose gets broken down by bacteria in the large intestine.

Soft dairy products, such as cottage cheese, sour cream, cream cheese, and ice cream tend to be higher in lactose than hard cheeses.

There are lactose-free milk and substitutions, such as soy, nut, oat, or rice milk. Vegetable oils and non-dairy spreads can be used instead of butter.⁵

Fruits and fructose

Any fruit or other food that is high in fructose, a type of sugar, can cause problems in people with IBS.
Common sources of fructose include stone fruits,⁶ such as peaches and pears, along with dried fruits, and fruit juice.⁷⁸

Fruits that are lower in fructose include

• Bananas
• Boysenberries
• Blueberries
• Cranberries
• Cantaloupe
• Grapes
• Kiwis
• Strawberries

Citrus fruits like oranges, lemons, and limes tend to be lower in fructose, but contain more acid which can also trigger IBS.⁹

Vegetables to avoid with IBS

Cruciferous and other vegetables

These include broccoli, Brussels sprouts, cabbage, cauliflower, kale, artichokes, onions, peppers, leeks, and asparagus.

Better Vegetable choices for people with IBS

These include:¹⁰

• Carrots
• Celery
• Green beans
• Eggplant
• Squash
• Sweet potatoes
• Yams
• Zucchini

Medication (pharmacologic agents) for IBS

Examples of drugs used to treat symptoms of IBS fall into the following categories:

• Anticholinergics such as dicyclomine and hyoscyamine
• Antidepressants
• Antidiarrheals such as diphenoxylate and loperamide
• Prokinetic agents to increase gut motility
• Serotonin receptor antagonists
• Bulk-forming laxatives
• Chloride channel activators (e.g., lubiprostone)
• Antispasmodics, such as peppermint oil, dicyclomine, and trimebutine ¹¹
• Guanylate cyclase C (GC-C) agonists such as linaclotide¹²
• Bacterial flora manipulation and anti-gas formation such as rifaximin

The FDA approved Rifaximin in 2015 for IBS-D.¹³. A 2012 review of the available research revealed that rifaximin was more effective than a placebo for overall symptom relief and bloating with minimal side effects.¹⁴¹⁵

Probiotics

People with the diarrhea subtype had issues with both Lactobacillus and Bifidobacterium bacteria levels. A systematic review evaluated 43 research articles on probiotics and demonstrated that probiotics helped to relieve symptoms of IBS, such as pain, distention or bloat, and gas ¹⁶

Probiotics are particularly useful for IBS-C and IBS-D. They correct abnormalities of the microbiome that can lead to IBS symptoms. The recommended supplement has a combination of lactobacillus and bifidobacterium with 10 billion colony forming units (CFU) and is enteric coated to prevent stomach acid from killing the bacteria.

Read our in-depth coverage of probiotics here.

Natural solutions for IBS symptoms

Psyllium supplements, a natural fiber found in Metamucil, can help all three types of IBS by increasing the stool caliber in diarrhea and drawing fluid into the intestines in the case of constipation. Adequate fluid intake is essential when a fiber is added according to the American Gastroenterological Association in a September 2017 study published in the International Journal of Molecular Medicine.

Because the GI tract can develop little tears due to inflammation, certain ‘bad’ sugars can gain access to the bloodstream and trigger the immune system to cause achiness. L-glutamine, an amino acid supplement can help heal the lining to prevent these leaks and can safely be used especially in IBS-D subtypes.¹⁷

Acupuncture can calm down the nervous system in people with IBS-C and IBS-D, electro-acupuncture can reduce stool frequency by sending a mild current through the acupuncture needles.

Acupuncture may even be helpful if you have IBS-D.¹⁸

CBT Cognitive Behavioral Therapy or CBT and other psychiatric interventions have shown utility for the symptoms of IBS. Hypnotherapy, dynamic psychotherapy, yoga, and relaxation techniques have been used but their utility has not been substantiated.

1. Bercik P, Verdu EF, Collins SM. Is irritable bowel syndrome a low-grade inflammatory bowel disease? Gastroenterol Clin North Am. 2005 Jun. 34 (2):235-45, vi-vii. [Medline].
2. Everson GT, “Gastrointestinal Motility in Pregnancy”, Gastroenterol Clin North Am. 1992 Dec;21(4):751-76
3. Detailed references can be found in our coverage of the FODMAP diet for IBS and IBD.
4. 5 Foods to Avoid if You Have IBS. Johns Hopkins Medicine. September 27, 2018.
5. Eat Any Sugar Alcohol Lately? Yale New Haven Health.
6. Fruits with a big pit – or stone – in the middle.
7. 5 Foods to Avoid if You Have IBS. Johns Hopkins Medicine. September 27, 2018.
8. Eat Any Sugar Alcohol Lately? Yale New Haven Health.
9. Irritable Bowel Syndrome. Mayo Clinic. March 17, 2018.
10. Eat Any Sugar Alcohol Lately? Yale New Haven Health.
11. Ruepert L, Quartero AO, de Wit NJ, van der Heijden GJ, Rubin G, Muris JW. Bulking agents, antispasmodics and antidepressants for the treatment of irritable bowel syndrome. Cochrane Database Syst Rev. 2011 Aug 10. CD003460. [Medline].
12. Rey E, Mearin F, Alcedo J, et al. Optimizing the use of linaclotide in patients with constipation-predominant irritable bowel syndrome: an expert consensus report. Adv Ther. 2017 Mar. 34 (3):587-98. [Medline]
13. Valeant Pharmaceuticals International, Inc. Salix announces FDA approval of Xifaxan 550 mg for the treatment of IBS-D (irritable bowel syndrome with diarrhea). Cision PR Newswire. May 27, 2015; Accessed: June 6, 2015
14. Menees SB, Maneerattannaporn M, Kim HM, Chey WD. The efficacy and safety of rifaximin for the irritable bowel syndrome: a systematic review and meta-analysis. Am J Gastroenterol. 2012 Jan. 107 (1):28-35; quiz 36. [Medline]
15. Pimentel M, Lembo A, Chey WD, et al, for the TARGET Study Group. Rifaximin therapy for patients with irritable bowel syndrome without constipation. N Engl J Med. 2011 Jan 6. 364 (1):22-32. [Medline]
16. Ford AC, Quigley EM, Lacy BE et al., “Efficacy of prebiotics, probiotics, and synbiotics in irritable bowel syndrome and chronic idiopathic constipation: systematic review and meta-analysis. Am J Gastroenterol. 2014 Oct. 109 (10):1547-61; quiz 1546, 1562. [Medline].
17. Benjamin, J., Makharia, G., Ahuja, V., Anand Rajan, K., Kalaivani, M., Gupta, S., & Joshi, Y. (2011). Glutamine and Whey Protein Improve Intestinal Permeability and Morphology in Patients with Crohn’s Disease: A Randomized Controlled Trial. Dig Dis Sci, 57(4), 1000-1012.
18. Liu ZH, Qi AZ,Li ZR et al. Pathological analysis of Irritable Bowel Syndrome in Chinese Medicine [J] Shaanzi Journal of TCM,2005,26(9):974–975.