Irritable Bowel Syndrome is a chronic idiopathic gastrointestinal disorder associated with altered bowel habits and abdominal pain. It begins usually in late teenage. It is more common in women almost two-thirds of Irritable Bowel Syndrome patients are women. Symptoms must be present for more than 6 months to diagnosis Irritable Bowel Syndrome. Almost half of the IBS patients have underlying psychological problems like anxiety or depression. Patients may also have dyspepsia, heartburn, fatigue or myalgia. Abnormal myoelectrical activity which causes abnormal motility of small and large intestine in Irritable Bowel Syndrome. Intestinal inflammation and visceral hypersensitivity play a great role in the pathogenesis of this disease.
Irritable Bowel Syndrome is a chronic disease with more than 6 months of symptoms. It is characterized by abdominal pain, bloating, constipation or diarrhea. Abdominal pain is usually crampy and intermittent and typically relieved by defecation. Pain is predominant in the lower abdomen. Bloating or visible abdominal distension may be a presenting symptom, may not be present always. Sometimes, patient complaints of hard stool in the early morning and loose stool thereafter.
Proper clinical history and physical examination are necessary to exclude the organic cause of these symptoms. ROME III diagnostic criteria are useful for differentiating IBS and functional constipation. These criteria must be fulfilled before diagnosis. Acute onset of symptoms suggestive of organic causes. Alarming symptoms like haematochezia, weight loss, severe constipation or diarrhea must be investigated properly as these occur unlikely in IBS. A family history of cancer or inflammatory bowel disease should be evaluated properly. Physical examination may be normal but lower abdominal tenderness can be present. A digital rectal examination should be performed in patients of IBS with constipation. Pelvic examination is necessary for postmenopausal women. Patients fulfilling IBS criteria without alarming symptoms, no investigation is needed. Incase of alarming symptoms association, it should be investigated thoroughly.
Blood tests like CBC, TSH, CRP, ESR, TG ( Tissue Transglutaminase) antibody may be done according to the symptoms colonoscopy and endoscopy can be needed especially for older people. USG of the whole abdomen or CT scan of the abdomen must be done where specific alarming symptoms present.
General Measures – As Irritable Bowel Syndrome is a functional disorder, patients should be reassured and educated regarding the disease. IBS is a chronic disease, hence patient should be informed about disease progression, treatment goals, and treatment processes. Symptoms may be exacerbated by stress, social factor, environmental factors and medications. Regular physical activity and exercise have a beneficial role in IBS.
Irritable Bowel Syndrome patients show dietary intolerance to specific foods. So, dietary modification is advised to live a symptom-free life. IBS patients should maintain a food diary to record foods that cause abdominal pain, bloating, diarrhea or constipation. Patients with excess flatulence should avoid it. Beans, onions, carrot, bananas, apricots, egg and meat. Avoiding carbohydrate-rich foods is another beneficial step to reduce symptoms. Fermentable oligo-di-and monosaccharides and polyols (“FODMAPS“) in patients with undergo fermentation and causes symptoms. ” FODMAPS ” include –
The majority of IBS patients don’t need drug therapy, they are well controlled by education, reassurance and diet therapy. Persistent cases are non-responsive to conservative therapy. Drug therapy that targetted to specific dominant symptoms gives better results.
ANTISPASMODIC DRUGS – These drugs are used to relieve abdominal pain in Irritable Bowel Syndrome. Anticholinergic drugs re commonly used for this purpose. Hyoscyamine, dicyclomine, methscopolamine is beneficial. These drugs should be used in elderly patients due to anticholinergic side effects like constipation, tachycardia, urinary retention and so on.
ANTI CONSTIPATION DRUGS – Patients suffering from IBS with constipation should be treated for constipation. Commonly used anti-constipation drugs like lactulose or sorbitol avoided usually due to a higher chance of flatulence and constipation. Newer anti-constipation drugs like Lubiprostone or Linaclotide are preferred for this purpose. Linaclotide is given orally as a single dose (290 mcg) and Lubiprostone is given orally (8mcg) twice daily. Polyethylene glycol can be used as an alternative.
ANTIDIARRHEAL DRUGS – The most common and most effective antidiarrheal drug is Loperamide. Loperamide 2mg is given orally three times per day. A new drug Eluxadoline is also found effective as an antidiarrheal agent. It is an opioid antagonist dose is given 75mg twice daily orally. Eluxadoline may cause pancreatitis or sphincter of Oddi dysfunction.
ANTIPSYCHOTIC DRUGS – TCA ( Tricyclic Anti Depressants) drugs give symptomatic relief specially from abdominal distension and pain. Imipramine, Desipramine or nortriptyline are used orally at bedtime. SSRI drugs like Fluoxetine, Citalopram, Sertraline are very beneficial for symptomatic improvement.