Table 2.

Pharmacological measures for IBS.

	Abdominal Pain	SII-D	SII-O
1st line	Antispasmodics (mebeverine): promote the relaxation of the intestinal smooth muscle through drugs with anticholinergic and muscarinic properties [56,70]	Opioid antagonists (loperamide): Prolong intestinal transit [70]	Osmotic laxatives (macrogol): improves the frequency and consistency of stools and has fewer adverse effects than other osmotic laxatives [56,71]
2nd line	Tricyclic antidepressants or serotonin reuptake inhibitors: have analgesic properties and act on intestinal motility [71,72]	Bile acid sequestrants (Cholestyramine): bile acid triggers diarrhea by stimulating colonic secretions [71]	Guanylate cyclase agonists: promote intestinal transit with an effect on abdominal pain and bloating [71]
		5-HT3 antagonists (Ondansetron): decrease motility and secretion in the colon [69]
		Rifaximin: can modulate gut flora and has a low risk for bacterial resistance [71]