Medicine may be used along with lifestyle changes to manage symptoms of irritable bowel syndrome (IBS). It may be prescribed to treat moderate to severe pain, diarrhea, or constipation that does not respond to home treatment.
Medicine can help relieve your symptoms enough to prevent them from interfering with your daily activities. It may not be possible to eliminate your symptoms.
In most cases, the choice of medicine is based on your most troublesome symptom. For example, if diarrhea is the most bothersome symptom, using antidiarrheals or anticholinergics may be helpful.
Few medicines have proved consistently helpful, and all medicines have side effects. So medicine should be used for specific symptoms that disrupt your normal daily activities.
Medicines that may be used to treat severe diarrhea that does not improve with home treatment include:
- Antidiarrheals, including atropine and diphenoxylate (such as Lomotil) and loperamide (such as Imodium).
- Bile acid binding agents, including cholestyramine (such as Prevalite).
- Rifaximin (Xifaxan), which has been shown to help people who have diarrhea and bloating as their worst symptoms. Rifaximin can be taken for 14 days. People who have symptoms again can be retreated for 14 days. This can be done one more time if needed.5
- Alosetron (Lotronex), which is used for some women who have severe diarrhea. This medicine has been shown to contribute to ischemic bowel disease. Specific guidelines for the use of alosetron require doctors who prescribe it to sign a certificate and patients to sign a consent form.
There are many medicines for severe constipation that doesn't improve with home treatment. Most of these medicines are available without a prescription and are okay to take once in a while. Check with your doctor before you use any of these medicines every day for constipation. Medicines for constipation include:
Pain and cramping
The following medicines may be used for long-term pain and cramping:
- Anticholinergics (antispasmodics). These include dicyclomine (Bentyl).
- Antidepressants, including desipramine (such as Norpramin). In low doses, they can help with pain caused by IBS.