1. Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by abdominal pain and changes in bowel habits without any detectable organic cause. 2. IBS has no known underlying pathology but is associated with alterations in gut motility, sensitivity, and brain-gut interactions. 3. Treatment aims to manage individual symptoms and typically involves dietary changes, antidiarrheals, antispasmodics, antidepressants, and cognitive-behavioral therapy. Lifestyle management and stress reduction are also important aspects of treatment.

1. Functional GIT Disorders& IRRITABLE BOWEL SYNDROME (IBS) Prepared by: Dr.Mohammad Shaikhani.

3. Introduction:IBS A chronic recurring abd pain or discomfort& altered bowel habits. One of the most common syndromes seen by GE ists/ PCPs, with a worldwide prevalence of 10-15%. In the absence of detectable organic causes, IBS is referred to as a functional disorder, defined by symptom-based diagnostic criteria known as the “Rome criteria”. IBS is one of several functional GI disorders (including functional dyspepsia); also frequently seen with IBS, as are other pain disorders, as fibromyalgia, chronic pelvic pain, interstitial cystitis. 20% of general population fulfill diagnostic criteria for IBS but only 10% of these consult their doctors because of GI symptoms. There is wide overlap with non-ulcer dyspepsia, chronic fatigue syndrome, dysmenorrhoea & urinary frequency.

4. Pathphysiology: Coexisting psychological conditions are also common, primarily anxiety, somatization, symptom-related fears (e.g., “I am worried that I will have severe discomfort during the day if I don’t empty my bowels completely in the morning”); contribute to impairments in quality of life, frequent absenteeism from work &excessive use of health care. Symptoms characteristic of IBS are common in healthy persons,but only 25-50% (typically those with more frequent or severe abd pain) seek medical care&there are substantial fluctuations in symptoms over time,or transitions to other complexes of GIsymptoms, as functional dyspepsia. Symptoms of IBS (or other related functional GI symptoms) frequently date back to childhood& significant proportion have a history of physical or sexual abuse ; with prevalence of IBS in children is similar to adults. The female-to-male ratio is 2:1 & higher among those who seek health care. IBS-like symptoms develop in 10% of adults after bacterial or viral enteric infections. RFs for postinfectious IBS include female sex, longer duration of ,psychosocial factors (including a major life stress at the time of infection& somatization).

5. Pathphysiology: Both initial presentations&exacerbations of IBS symptoms are often preceded by major psychological or by physical stressors (e.g., GI infection). Given the direct association between symptoms & stress, the frequent coexisting psychiatric conditions&the responsiveness of symptoms in many persons to therapies directed at the CNS, IBS is often described as a “brain–gut disorder,” although its pathophysiology remains uncertain. Alterations in GI motility&the balance of intestinal absorption &secretion may underlie irregularities in bowel habits & mediated in part by dysregulation of the gut-based serotonin signaling system. Increased perception of visceral stimuli may contribute to abdominal pain & discomfort. Alterations in immune activation of the mucosa&intestinal microflora contribute to symptoms, yet its causative role unclear.

6. Evaluation: Physical examination: Frequently reveals tenderness in the LLQ over a palpable sigmoid colon. DRE is warranted to rule out rectal disease & abnormal function of the anorectal sphincter (e.g., paradoxical pelvic-floor contraction during a defecation attempt), which may contribute to symptoms of constipation.

7. Evaluation :Diagnosis In patients who have symptoms that meet the Rome criteriado not have warning signs(rectal bleeding,anemia, weight loss, fever, family H/O CRC, onset of the first symptom after 50 years& a major change in symptoms). IBS ,can generally be diagnosed without additional testing beyond a careful history taking, a general physical exam& routine lab (not including colonoscopy) Patients should be sub classified as having diarrhea-predominant IBS, constipation-predominant IBS, or mixed bowel habits.

8. Evaluation :DD In patients who meet the Rome criteria&have no warning signs, the DD includes: For diarrhea-predominant IBS: Celiac sprue Microscopic Collagenous colitis Atypical Crohn’s disease For constipation-predominant IBS. Chronic constipation (without pain).

11. Management : Stressors, psychae A relationship between symptoms & food intake, as well as possible triggers for the onset of symptoms(e.g GI infection or marked stressors) should be assessed, since this may guide treatment recommendations. Attention should be paid to symptoms that suggest other functional GI/ somatic pain disorders & psychological conditions often associated with IBS.

12. Management : good doc-pat relationship. Accepting the patient’s symptoms /distress as real& not simply as a manifestation of excessive worrying& somatization& providing the patient with a plausible model of the disease (e.g., “brain–gut disorder”) facilitates the establishment of a positive patient–doctor relationship. Evidence suggests that an approach that includes acknowledging the disease, educating the patient about the disease, reassuring the patient may improve the treatment outcome.

13. Pharmacologic Treatment Symptomatic treatment (usually aimed at normalizing bowel habits or decreasing abdominal pain) by a reassuring health care provider typically provides relief for patients with mild symptoms who are seen in primary care settings. The treatment of patients with more severe symptoms remains challenging. Only a small number of pharmacologic/psychological treatments supported by well-designed RCTs. Treatment of IBS with currently available drugs usually is targeted to the management of individual symptoms, such as constipation, diarrhea, &abdominal pain

15. Constipation Osmotic laxatives are often useful in the treatment of constipation. Fiber/other bulking agents have also been used as initial therapy,but the frequent side effects (in particular, an increase in bloating) &inconsistent, largely negative results of trials have decreased their use. Tegaserod, a partial (5-HT4 )–receptor agonist, moderately effective for global relief of symptoms in patients with IBS, 20% more likely to have global relief of symptoms, but its marketing suspended in March 2007, for significant increase in the number of CV ischemic events (MI, stroke, unstable angina) in patients withknown CVD, CV RFs, or both. In July 2007, FDA approved an investigational new- drug program for tegaserod with acces restricted to women < 55 years who have constipation-predominant IBS (or chronic constipation) without known CV problems.

16. Diarrhea Antidiarrheal agents in diarrhea- predominant IBS: generally effective. Regular use of low doses (e.g., 2 mg of loperamide every morning or twice a day) effective for the treatment of otherwise uncontrollable diarrhea& may decrease patients’ anxiety about uncontrollable urgency and fecal soiling. A 5-HT3–receptor antagonist alosetron at a dose of 1 mg twice a day for 12 weeks decreased stool frequency & bowel urgency, relieved abdominal pain and discomfort,improved scores for global IBS symptoms (i.e., adequate relief of IBS symptoms), improved health-related QOL in both women & men. FDA has restricted the use of the drug because of rare but serious adverse effects, including complications from constipation (ileus, bowel obstruction, fecal impaction, perforation& ischemic colitis Alosetron is indicated only for women with severe diarrhea-predominant IBS who have had symptoms for at least 6 months& not had a response to conventional therapies (in particular, antidiarrheal agents).

17. Abdominal Pain Antispasmodics (e.g., hyoscyamine or mebeverine) used for pain TAD are commonly used often in low doses(e.g., 10 to 75 mg of amitriptyline)., acting by antihyperalgesia,improvement in sleep, normalization of GI transit, & at higher doses (e.g., 100 mg or more at bedtime), treatment of coexisting depression / anxiety. Despite their frequent use in practice,their efficacy are inconsistent.

18. Cognitive–Behavioral Therapy A combination of cognitive /behavioral techniques; is the best studied psych trt. Cognitive techniques (typically group or individual in 4 to 15 sessions) are aimed at changing catastrophic or maladaptive thinking patterns underlying the perception of somatic symptoms. Behavioral techniques aim to modify dysfunctional behaviors through relaxation techniques, contingency management(rewarding healthy behaviors), or assertion training. Some RCTs shown reductions in IBS symptoms with the use of gut-directed hypnosis (aimed at improving gut function), which involves relaxation, change in beliefs&self-management. Comparisons of psychotherapy with pharmacotherapy or psychotherapy plus pharmacotherapy with pharmacotherapy alone are lacking. Improvement reported with psychological treatments seems to be similar to or greater than that reported with medications Behavioral treatments, (including hypnosis), as compared with control treatments (including waiting list, symptom monitoring,& usual medical treatment), significantly more likely to have a reduction in GI symptoms of at least 50%.