What is the cause of fluctuating constipation characterized by irregular bowel movements, predominant constipation, and occasional diarrhea, despite using Colace (docusate) and Miralax (polyethylene glycol), and what are the appropriate management options for this patient's symptoms of constipation, bloating, and stomach discomfort?

From the Guidelines

I strongly recommend switching from Colace (docusate sodium) to Miralax (polyethylene glycol) as the primary treatment for your chronic constipation, as Miralax is more effective for chronic constipation management 1.

Current Situation

You are experiencing constipation with irregular bowel movements, characterized by predominant constipation and occasional diarrhea, and have been using Colace and Miralax. You have also used glycerin suppositories twice and have recently increased your Colace intake to twice daily due to recent constipation episodes.

Recommendations

• Take one capful (17g) of Miralax dissolved in 8 ounces of water every morning to help manage your chronic constipation, as recommended by the American Gastroenterological Association-American College of Gastroenterology clinical practice guideline 1.
• Consider adding a fiber supplement like psyllium husk (Metamucil), starting with 1 teaspoon daily and gradually increasing to 1 tablespoon twice daily, but note that the evidence for fiber supplementation is conditional and based on low certainty of evidence 1.
• Drink at least 64 ounces (8 cups) of water daily to help the fiber work properly.
• Incorporate regular physical activity, such as 20-30 minutes of walking daily, to stimulate bowel motility.
• Establish a consistent bathroom routine, particularly after meals when the gastrocolic reflex is strongest.
• For breakthrough constipation, use osmotic laxatives like Miralax rather than stimulant laxatives, which can create dependence.
• Your symptoms of bloating, irregular bowel movements alternating between constipation and diarrhea, and abdominal discomfort suggest possible Irritable Bowel Syndrome with Constipation (IBS-C), and the lack of urge to defecate may indicate pelvic floor dysfunction or slow transit constipation.

Next Steps

If these measures do not provide relief within 2-3 weeks, consult a gastroenterologist for further evaluation, as prescription medications or additional testing may be needed 1.

From the FDA Drug Label

The primary endpoint of the studies was SBM frequency. The studies demonstrated that patients treated with lubiprostone had a higher frequency of SBMs during Week 1 than the placebo patients. Signs and symptoms related to constipation, including abdominal bloating, abdominal discomfort, stool consistency, and straining, as well as constipation severity ratings, were also improved with lubiprostone versus placebo.

The patient's symptoms of constipation, including abdominal bloating and abdominal discomfort, may be improved with lubiprostone. The drug has been shown to increase the frequency of spontaneous bowel movements (SBMs) and improve constipation severity ratings. However, it is essential to consult a healthcare professional to determine the best course of treatment for this patient's specific condition 2.

• The patient's experience of constipation and occasional diarrhea may be related to their condition, but the FDA drug label does not provide direct information on this specific situation.
• The use of glycerin suppositories and Colace may be a part of the patient's treatment plan, but the FDA drug label for lubiprostone does not address the interaction between these medications and lubiprostone.
• The patient's consideration of fiber supplements and increase in water intake may be beneficial for managing constipation, but the FDA drug label for lubiprostone does not provide information on these specific interventions 2.

From the Research

Constipation Management

• The individual is experiencing fluctuating constipation with irregular bowel movements, predominant constipation, and occasional diarrhea, and has been using Colace and Miralax to manage their symptoms 3, 4, 5.
• They have also used glycerin suppositories twice, once in November and once in March, when constipation was severe, and have recently increased their Colace dosage to twice daily due to recent constipation episodes.

Effectiveness of Current Treatment

• Studies have shown that psyllium is superior to docusate sodium for treating chronic constipation, increasing stool water content and laxative efficacy 3.
• A review of laxative therapies for chronic constipation in older adults found that psyllium and calcium polycarbophil were more effective than docusate sodium in increasing stool frequency 4.
• Another study found that docusate did not show any benefits for constipation when compared with placebo or psyllium, and that psyllium and sennosides were more effective than docusate 5.

Alternative Treatment Options

• Increasing water intake and considering fiber supplements may be beneficial in managing constipation, as the individual has been trying various methods to manage their symptoms.
• The use of laxatives such as lactulose, polyethylene glycol, and senna may also be effective in increasing stool frequency, as shown in various studies 4.
• Lubiprostone has also been associated with an increase in spontaneous bowel movements per week compared to placebo 4.