Patients with irritable bowel syndrome usually present with the following symptoms:

Colicky abdominal pain: Patients with irritable bowel syndrome suffer from acute episodes of sharp, colicky pain in the lower abdomen. This pain is often relieved by defecation.

Altered Bowel Habits: Both constipation and diarrhea can occur in the patients suffering from irritable bowel syndrome, however, one of them may predominate in a single patient. Those with constipation pass hard, infrequent stools. In contrast, those with diarrhea have low volume stools but with frequent defecation.

Abdominal distension: Bloating and gas causes abdominal distention in these patients. Abdominal distention typically worsens during the day.

Other symptoms: Patients of irritable bowel syndrome may have sexual dysfunction, urinary frequency, urgency and dysuria may be present. Other non-specific symptoms include nausea, vomiting and heart burn.

• Pain

  It is indicated for adults with IBS-D. 8 Serious AEs are possible, such as pancreatitis and a spasm in the sphincter of Oddi, which is extremely painful. Other AEs include constipation, nausea, and abdominal pain. Dr. [pharmacytimes.com]

  Common symptoms are abdominal pain or discomfort with either an alteration in bowel movement form or frequency. Other symptoms such as the relief of pain or discomfort by opening the bowels, or abdominal bloating can occur with IBS. [ed.ac.uk]

  Expert commentary: Pain is the main contributor to severity in IBS. Seeking pain alleviation is the most common reason that IBS sufferers consult with their physicians. [ncbi.nlm.nih.gov]

  Fibromyalgia Fibromyalgia is part of a general class of chronic musculoskeletal pain syndromes. It is a pain disorder that leads to several painful points over muscles. [news-medical.net]

  Eliciting the quality of the pain may distinguish between these two entities as cholestatic pain is typically more sharp and intense. [clinicaladvisor.com]

• Fatigue

  There are characteristic symptoms of generalized muscle stiffness, pain, fatigue and an abnormal sleep pattern. After osteoarthritis and rheumatoid arthritis, fibromyalgia is one of the most common disorders seen in community rheumatology practice. [news-medical.net]

  Studies of IBS among patients with chronic fatigue syndrome have reported a prevalence ranging from 35-92%. The prevalence of IBS among patients with chronic fatigue syndrome is reported to be 14%. [ncbi.nlm.nih.gov]

  In the mid 19th century Beard, 55 an American neurologist, published a paper on "neurasthenia", a term he used to describe individuals with unexplained chronic fatigue and lassitude (nervous exhaustion). [doi.org]

• Surgical Procedure

  Subjects with and without IBS, respectively, reported the following surgical procedures: cholecystectomy, 569 (12.4%) versus 3428 (4.1%), P < 0.0001; appendectomy, 967 (21.1%) versus 9906 (11.7%), P < 0.0001; hysterectomy, 1063 (33.2%) versus 6751 (17.0% [ncbi.nlm.nih.gov]

  Patients with IBS have an increased risk for abdominopelvic and gallbladder surgery and, thus, an associated risk for experiencing morbidity and mortality associated with these surgical procedures. [doi.org]

  It is not uncommon for those who suffer from IBS to undergo unnecessary surgical procedures. [livescience.com]

  Equality and diversity considerations People from different cultures who need certain surgical procedures for inflammatory bowel disease, such as stoma operations, may need additional support if such procedures are not considered acceptable in their community [pathways.nice.org.uk]

• Abdominal Pain

  Common symptoms are abdominal pain or discomfort with either an alteration in bowel movement form or frequency. Other symptoms such as the relief of pain or discomfort by opening the bowels, or abdominal bloating can occur with IBS. [ed.ac.uk]

  It is indicated for adults with IBS-D. 8 Serious AEs are possible, such as pancreatitis and a spasm in the sphincter of Oddi, which is extremely painful. Other AEs include constipation, nausea, and abdominal pain. Dr. [pharmacytimes.com]

  Other symptoms may include abdominal pain that is relieved after defecation, mucus in the stools, or a sensation of incomplete rectal evacuation. [britannica.com]

  The incidence of cholecystectomy was higher in irritable bowel syndrome and abdominal pain and normal bowel groups than in controls and altered bowel and no abdominal pain group. [ncbi.nlm.nih.gov]

  When propulsion of the intestinal contents is impaired it can lead to abdominal pain and spasms. [clinicaladvisor.com]

• Constipation

  […] is common. • IBS-M: Both diarrhea and constipation are common (mixed). • IBS-U: Neither diarrhea nor constipation are common (unsubtyped). [pharmacytimes.com]

  Patients may also present with a history of constipation, diarrhea, or alternating constipation and diarrhea. The stools may be mixed with mucous. [clinicaladvisor.com]

  Some foods and drinks trigger constipation (IBS-C) and some trigger diarrhea (IBS-D). [emedicinehealth.com]

  Saito, James Moriarty and Cathy Schleck, A case-control comparison of direct healthcare-provider medical costs of chronic idiopathic constipation and irritable bowel syndrome with constipation in a community-based cohort, Journal of Medical Economics, [doi.org]

  Stool softeners and fiber may soften stools of individuals who are constipated. IBS Treatment: Drugs for Constipation An effective way to reduce constipation is to increase the fluid in the intestine to soften the stools. [onhealth.com]

• Diarrhea

  […] is common. • IBS-C: Constipation is common. • IBS-M: Both diarrhea and constipation are common (mixed). • IBS-U: Neither diarrhea nor constipation are common (unsubtyped). [pharmacytimes.com]

  IBS-D is irritable bowel syndrome with diarrhea. [emedicinehealth.com]

  This pearl will help distinguish organic diarrhea (e.g., Inflammatory bowel disease (IBD) or infectious diarrhea) from secretory diarrhea. IBS may cause abdominal bloating and gassiness. [clinicaladvisor.com]

  Convert to ICD-10-CM : 564.1 converts approximately to: 2015/16 ICD-10-CM K58.9 Irritable bowel syndrome without diarrhea Approximate Synonyms Colon spasm Colon spasm w diarrhea Colon spasm with diarrhea Colonospasm Irritable bowel syndrome w diarrhea [icd9data.com]

  Changes in symptoms (eg, in the location, type, or intensity of pain; in bowel habits; in constipation and diarrhea) and new symptoms or complaints (eg, nocturnal diarrhea) may signal another disease process. [merckmanuals.com]

• Dyspepsia

  The following diagnoses were also made: IBS (100/137, 73%), functional dyspepsia (62/137, 45%), organic dyspepsia (33/137, 24%), and lactose intolerance (75/137, 55%). [ncbi.nlm.nih.gov]

  (FD: functional dyspepsia; OD: organic dyspepsia). [doi.org]

• Flatulence

  Ispaghula therapy resulted in improvement in global symptoms and satisfying bowel movements (P less than 0.001) but produced no change in abdominal pain or flatulence. [ncbi.nlm.nih.gov]

  There are several natural causes of flatulence. Flatulence can also be caused by some health conditions related to the digestive system, or as a side effect of certain medicines." Bloating "Bloating is a common symptom in IBS. [home.bt.com]

  Flatulence Ten studies evaluated the effects of probiotics on flatulence (5,6,26,28,30-32,36,37,39). [doi.org]

• Flushing

  A person should also see a doctor if their symptoms get progressively worse, stools are pale, bulky, very offensive smelling and difficult to flush away (this may indicate a problem with absorbing fat), or if they are concerned about their symptoms. [mydr.com.au]

  Metcalfe DD (2000) Differential diagnosis of the patient with unexplained flushing/anaphylaxis. Allergy Asthma Proc 21(1):21–24 CrossRef PubMed Google Scholar 31. Lafont E et al (2014) Causes and diffential diagnosis of flush. [doi.org]

• Acne Vulgaris

  Many skin diseases, including acne vulgaris, are associated with higher serum levels of SP [ 69 ], which can be induced by blockage of DPP IV [ 65 ]. [dx.doi.org]

• Dysmenorrhea

  Mannix, Menstrual-Related Pain Conditions: Dysmenorrhea and Migraine, Journal of Women's Health, 17, 5, (879), (2008). B. [doi.org]

  […] circadian rhythm, history of abuse, anxiety, and depression [2] [1] It has also been seen with many other pain syndromes and functional disorders such as fibromyalgia, chronic fatigue syndrome, tempromandibular joint disorder, chronic pelvic pain, and dysmenorrhea [physio-pedia.com]

  […] that 26 percent of children with recurrent abdominal pain were diagnosed with IBS, making it a common reason for school absenteeism. 7 Seventy percent of patients with IBS are women; 48 to 79 percent of patients with chronic pelvic pain, dyspareunia, dysmenorrhea [web.archive.org]

• Headache

  Headache. 2014 Nov-Dec;54(10):1644-6. doi: 10.1111/head.12429. Epub 2014 Jul 18. Author information 1 Montefiore Headache Center, Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA. [ncbi.nlm.nih.gov]

  After a headache specialist determined headache frequency and diagnosis (based on criteria of the second International Classification of Headache Disorders), patients completed a self‐administered electronic survey with information on demographics, headache‐related [doi.org]

  These include rheumatologic symptoms, such as skin rashes, muscle contractions, muscle pain (myalgia), headache etc. These symptoms have been seen in nearly two-thirds of irritable bowel syndrome patients. [news-medical.net]

The diagnosis of irritable bowel syndrome is difficult. It was once considered a diagnosis of exclusion; however, this belief is no longer valid. The diagnosis is based on history, general physical examination, laboratory investigations and radiographic studies [6].

The findings in history and general physical examination often indicate iron deficiency anemia. Weight loss is also a common feature. A family history of certain gastrointestinal disorders including celiac disease, inflammatory bowel disease and colorectal carcinoma is often present.

The following investigations are necessary to establish the diagnosis with certainty.

Blood studies

Blood studies include:

• Complete blood count: This is used to rule out anemia, inflammation and infection.

• Electrolyte levels: They can demonstrate electrolyte imbalance and dehydration in metabolic disorders.

Stool examination

Stool examination is performed to exclude infection or infestation as the cause of diarrhea.

History-specific examinations

History-specific examinations in irritable bowel syndrome include:

• Hydrogen breath test
  This test excludes bacterial overgrowth in patients presenting with diarrhea and the complaints of lactose and fructose intolerance.
• Tissue transglutaminase antibody test
• Thyroid function test
• Erythrocyte sedimentation rate
• C-reactive protein

History specific imaging studies

These studies include:

• Barium studies of the upper gastrointestinal tract are performed to detect any obstruction or inflammatory condition (such as Crohn’s disease)
• Abdominal CT scan is also required to look for tumors, obstruction and pancreatic diseases.

History specific procedures
History specific procedures include:

• Anal manometry (to detect rectal distention)
• Flexible sigmoidoscopy (to evaluate the presence of distal obstruction)
• Colonoscopy (to look for polyps or carcinoma in the colon) [7]

• Colitis

  Irritable Bowel Syndromes, Mucous Colitides, Syndrome, Irritable Bowel, Syndromes, Irritable Bowel, Irritable Colon, Mucous Colitis, Mucous colitis, Irritable colon syndrome, Spastic colon, Adaptive colitis, Membranous colitis, Colon spasm, Functional [fpnotebook.com]

  Over the years, the unexplained gastrointestinal symptoms of the irritable bowel syndrome have been described in various terms, including mucous colitis, spastic colitis, nervous colon, and irritable colon. [dx.doi.org]

The management of irritable bowel syndrome includes dietary measures and psychological support.

Dietary measurements

The dietary measures that are recommended in the patients suffering from irritable bowel syndrome are listed below.

• Fiber supplementation is essential to improve symptoms of constipation and diarrhea
• Polycarbophil compounds (Fibercon) are highly recommended
• Adequate water intake is necessary
• Caffeine avoidance is recommended to limit anxiety
• Legumes should be avoided to limit bloating
• Lactose and/or fructose intake should be restricted
• Gluten free diet is also beneficial [8]

Drugs

A number of other drugs have a beneficial role in the management of irritable bowel syndrome. These drugs are:

• Alosetron (a nerve receptor antagonist specifically used for irritable bowel syndrome) [9][10]
• Anti-cholinergics (such as dicyclomine and hyoscyamine)
  Anti-diarrheals (such as loperamide)
• Tricyclic anti-depressants (such as imipramine and amitriptyline)
• Anti-biotics (such as rifaximin)

The life expectancy in the patients suffering from this disease is the same as that in healthy population. Female patients may have an increased risk of ectopic pregnancies and miscarriages; however, there is no association with stillbirth.

The quality of life is also affected. Work absenteeism is more common in such patients due to severe abdominal pain and altered bowel habits.

There is no specific cause for the development of irritable bowel syndrome.

Enteric infection may lead to the development of irritable bowel syndrome in the majority of the cases. A study demonstrated the prevalence of irritable bowel syndrome in patients suffering from enteritis caused by Giardia lamblia to be as high as 46.1% as opposed to only 14% in the controls [1]. 

Since irritable bowel syndrome is more common in families, genetic factors may also play a predisposing role. Other predisposing factors include inflammatory processes like food intolerance, lack of dietary fibers in the diet and alterations in the gut microbiota [2] [3]. Anxiety, excessive worry and sexual or physical abuse are also contributing factors.

Irritable bowel syndrome affects both men and women and occurs most commonly in individuals between 30 and 50 years of age. In Western countries, female-to-male ratio is 2:1. According to the epidemiological data from the United States, around 5 to 9% of men and 14 to 24% of women are affected.

The global incidence of irritable bowel syndrome is estimated to be 1-2% annually while the prevalence is around 10 to 15%. Prevalence is similar in white and black population but lower in Hispanics.

The pathogenesis of irritable bowel syndrome includes several components which are further explained below:

Altered gastrointestinal motility: The electrical activity of the bowel is disturbed which causes altered gastrointestinal motility of both the small and large gut.

Visceral hyperalgesia: There is hypersensitivity of the small and large gut is increased, particularly with rapid distention. This is more common in women and in the patients in whom this disease is predominantly characterized by diarrhea.

Psychopathology: There is no well-known association between psychopathic disturbances and the pathogenesis of irritable bowel syndrome. Yet, patients under medical care are highly prone to the development of depression, panic and anxiety. These patients usually present with history of suicidal attempts [4].

Microscopic inflammation: Inflammation of both the colon and the small bowel have been demonstrated in the patients suffering from irritable bowel syndrome [5]. The number of lymphocytes and enteroendocrine cells in the bowel is also increased. The latter secrete serotonin, the action of which causes diarrhea.

Irritable bowel syndrome can be prevented by ensuring proper hygiene. The use of high fiber diet is also helpful.

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder that is characterized by abdominal pain, altered bowel habits (diarrhea, constipation or both) without any underlying obvious pathologic change in the small and large gut. The disease is not life threatening condition but it can disrupt the quality of life.

Irritable bowel syndrome is a disorder in which the motility of the large gut and small gut are disturbed. The patients usually develop abdominal discomfort and altered bowel habits. The disease runs in families usually affecting the younger age group.

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2. Shepherd SJ, Parker FC, Muir JG, Gibson PR. Dietary triggers of abdominal symptoms in patients with irritable bowel syndrome: randomized placebo-controlled evidence. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. Jul 2008;6(7):765-771.
3. Kassinen A, Krogius-Kurikka L, Makivuokko H, et al. The fecal microbiota of irritable bowel syndrome patients differs significantly from that of healthy subjects. Gastroenterology. Jul 2007;133(1):24-33.
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10. Bardhan KD, Bodemar G, Geldof H, et al. A double-blind, randomized, placebo-controlled dose-ranging study to evaluate the efficacy of alosetron in the treatment of irritable bowel syndrome. Alimentary pharmacology & therapeutics. Jan 2000;14(1):23-34.