What can be used to treat constipation-predominant irritable bowel syndrome (IBS)?

From the Guidelines

Constipation-predominant irritable bowel syndrome (IBS-C) can be effectively treated with linaclotide (Linzess) at 145-290 mcg once daily, as recommended by the AGA with high certainty in the evidence of effects. This treatment option is supported by the most recent and highest quality study, which suggests that linaclotide stimulates the GC-C receptor on enterocytes, resulting in intestinal chloride and bicarbonate secretion and inhibiting colonic nociceptors 1.

Treatment Options

Other treatment options for IBS-C include:

• Fiber supplements like psyllium (Metamucil) at 3-12 grams daily or methylcellulose (Citrucel), which add bulk to stool and improve transit time
• Osmotic laxatives such as polyethylene glycol (MiraLAX) at 17 grams daily mixed in water, which draw water into the intestines
• Lubiprostone (Amitiza) at 8 mcg twice daily, which increases chloride influx into the lumen of the gastrointestinal tract, resulting in acceleration of intestinal transit 1
• Plecanatide (Trulance) at 3 mg daily, which works similarly to linaclotide by stimulating the GC-C receptor

Lifestyle Modifications

In addition to these treatment options, lifestyle modifications are also important, including:

• Increased water intake (at least 8 glasses daily)
• Regular physical activity
• A diet low in gas-producing foods These modifications can help address the underlying causes of constipation in IBS and improve overall symptoms.

Evidence-Based Recommendation

The recommendation to use linaclotide for IBS-C is based on the most recent and highest quality study, which provides strong evidence for its effectiveness 1. This study suggests that linaclotide is a effective treatment option for IBS-C, with a strong recommendation and high certainty in the evidence of effects.

From the FDA Drug Label

Lubiprostone is indicated for the treatment of irritable bowel syndrome with constipation (IBS-C) in women at least 18 years old. LINZESS is a guanylate cyclase-C agonist indicated for treatment of: Irritable bowel syndrome with constipation (IBS-C) in adults.

Treatment options for constipation-predominant irritable bowel syndrome (IBS-C) include:

• Lubiprostone (PO): indicated for the treatment of IBS-C in women at least 18 years old 2
• Linaclotide (PO): indicated for the treatment of IBS-C in adults 3

From the Research

Treatment Options for Constipation-Predominant Irritable Bowel Syndrome (IBS-C)

• Lubiprostone, a selective chloride channel-2 activator, has been shown to be effective in increasing fluid secretion in the intestinal apical cell membrane, increasing gut motility and frequency of stool passage, and alleviating abdominal discomfort/pain 4, 5.
• Fiber supplements, such as soluble and insoluble fiber, may have a limited role in empiric therapy, especially if constipation is the most significant symptom, but may not be significantly more effective than placebo at relieving global IBS symptoms 6, 7.
• Osmotic or stimulant laxatives are also commonly used to treat constipation-predominant IBS, but may exacerbate the condition or cause electrolyte disturbances 4.
• Other treatment options, such as psychotropic agents, hypnotherapy, and smooth muscle relaxants, may be used to relieve symptoms such as pain, diarrhea, and depression associated with IBS-C, but their overall efficacy is unclear 7.

Mechanism of Action and Efficacy

• Lubiprostone has been shown to increase spontaneous bowel movement frequency, improve stool consistency, and decrease straining, bloating, and severity of constipation in patients with IBS-C 4, 5.
• The efficacy of lubiprostone has been demonstrated in two phase III studies, with beneficial effects continuing for up to 4 weeks after cessation of treatment 4.
• Fiber supplements have been shown to have a limited role in empiric therapy, with some studies suggesting that soluble fiber may be more effective than insoluble fiber in relieving symptoms 6.

Safety and Tolerability

• Lubiprostone has been shown to be well tolerated in the long-term, with nausea and diarrhea being the most common adverse events 4, 5.
• Fiber supplements may cause abdominal discomfort and bloating, especially if introduced too quickly or in high doses 6.
• Other treatment options, such as laxatives and psychotropic agents, may have their own set of adverse events and interactions, and should be used with caution and under medical supervision 4, 7.