Drugs to Treat Irritable Bowel Syndrome

Irritable bowel syndrome refers to a medical problem affecting the gastrointestinal system. According to the Mayo Clinic, symptoms of this condition include stomach pain or cramping, a gas, a bloated feeling, diarrhea, constipation and mucus in the stool. In fact, 1 in 5 Americans suffer from irritable bowel syndrome. Fortunately, drugs to treat irritable bowel syndrome exist.


Psyllium, commonly sold as Metamucil, is a bulk-forming laxative that actually softens and makes the stool bulkier. This medication does this by way of absorbing liquid in the intestines. This drug treats constipation and bowel irregularity.

Drugs.com says that psyllium’s less concerning side effects include bloating and a change in bowel habits. Tell a physician when psyllium’s less serious side effects last for more than seven days.

Psyllium’s serious side effects include trouble swallowing, choking, cramping, vomiting and nausea. In some instances, psyllium causes rectal bleeding, constipation that lasts for more than seven days and an itchy skin rash. Tell a doctor when psyllium’s serious side effects develop.

A change in psyllium’s dose may be necessary when suffering from rectal bleedin or intestinal blockage.

Metamucil is a powder that must be mixed with water and taken daily or as directed.


Lubiprostone, commonly sold as Amitiza, is another medication taken to reduce bloating, stomach pain and straining. In fact, this medication specifically treats irritable bowel syndrome with constipation, especially in women who are at least 18 years old, says MedlinePlus.

Lubiprostone’s less serious side effects include nausea, a headache, dizziness, chest discomfort and swelling of the feet, ankles, legs and hands. In some instances, this medication leads to fatigue, gas, vomiting, bloating and stomach pain. Talk to a physician when lubiprostone’s less serious side effects last for greater than five days.

Lubiprostone’s serious side effects include a rash, shortness of breath, throat tightness and swelling of the mouth, throat, face and lips. Go to the emergency room when these symptoms develop.

Lubiprostone is a capsule taken twice a day.


Alosetron, commonly sold as Lotronex, is another medication that decreases irritable bowel symptoms. Specifically, it slows stool movement throughout the intestines.

Drugs.com says that alosetron’s less serious side effects include bloating, nausea, rectal hemorrhoids, gas and bloating. In some instances, alosetron also leads to a skin rash, heartburn, stomach discomfort and nausea. Tell a physician when alosetron’s less serious side effects remain for greater than 5 days.

Alosetron’s serious side effects include worsening stomach pain, rectal bleeding and a fast or uneven heartbeat. Inform a doctor when alosetron’s serious side effects develop.

Avoid taking alosetron if you suffer from constipation, intestinal perforation or obstruction, ulcerative colitis, diverticulitis, liver disease or diverticulitis.

Alosetron is a tablet taken daily or as indicated.

About this Author

Lisabetta Divita is a physician whose love for writing flourished while she was exposed to all facets of the medical field during her training. Her writings are currently featured in prominent medical magazines and LIVESTRONG. She holds a Doctorate in medicine, Masters in biomedicine, and Bachelors of Science in biology from Boston College.