Mebeverine is a drug used to alleviate some of the symptoms of irritable bowel syndrome. It works by relaxing the muscles in and around the gut. Mebeverine is a drug used to alleviate some of the symptoms of irritable bowel syndrome. It works by relaxing the muscles in and around the gut. Mebeverine is used to alleviate some of the symptoms of irritable bowel syndrome (IBS) and related conditions; specifically stomach pain and cramps, persistent diarrhea, and flatulence. Data from controlled clinical trials have not found a difference from placebo in the alleviating stomach pain in people with IBS. It has not been tested in pregnant women nor in pregnant animals so pregnant women should not take it; it is expressed at low levels in breast milk, while no adverse effects have been reported in infants, breastfeeding women should not take this drug. Adverse effects include hypersensitivity reactions and allergic reactions, immune system disorders, skin disorders including hives, edema and widespread rashes. Additionally, the following adverse effects have been reported: heartburn, indigestion, tiredness, diarrhea, constipation, loss of appetite, general malaise, dizziness, insomnia, headache, and decreased pulse rate. It does not have systemic anticholinergic side effects. Mebeverine can, on highly rare occasions, cause drug-induced acute angle closure glaucoma. Mebeverine is an anticholinergic but its mechanism of action is not known; it appears to work directly on smooth muscle within the gastrointestinal tract and may have an anesthetic effect, may affect calcium channels, and may affect muscarinic receptors.