What are the causes and treatments of severe constipation?

From the Guidelines

For severe constipation, I recommend starting with lifestyle changes and over-the-counter medications before seeking medical attention if symptoms persist, as suggested by the American Gastroenterological Association and the American College of Gastroenterology in their 2023 clinical practice guideline 1. To manage severe constipation, consider the following steps:

• Increase fluid intake to at least 8 glasses of water daily
• Add more fiber to the diet, aiming for 25-30g daily
• Engage in regular physical activity For immediate relief, options include:
• Osmotic laxatives like MiraLAX (polyethylene glycol) at a dose of 17g mixed in 8oz of water once daily for up to 7 days
• Stimulant laxatives such as bisacodyl (Dulcolax) 5-10mg orally or senna (Senokot) 8.6-17.2mg at bedtime, which can provide relief within 6-12 hours
• A glycerin or bisacodyl suppository for faster relief
• Docusate sodium (Colace) 100mg twice daily to help soften hard stools It is essential to note that severe constipation can be a symptom of a more serious condition, and if symptoms include severe abdominal pain, bloody stools, vomiting, or if constipation lasts more than two weeks despite these measures, immediate medical attention is necessary, as indicated by various studies, including those published in Gut in 2020 and 2021 1.

From the FDA Drug Label

The efficacy of LINZESS for the treatment of CIC was established in two double-blind, placebo-controlled, randomized, multicenter clinical trials in adult patients (Trials 3 and 4) A total of 642 patients in Trial 3 and 630 patients in Trial 4 [overall mean age of 48 years (range 18 to 85 years), 89% female, 76% white, 22% black, 10% Hispanic] received treatment with LINZESS 145 mcg, 290 mcg, or placebo once daily and were evaluated for efficacy. All patients met modified Rome II criteria for functional constipation The CSBM responder rates are shown in Table 6 During the individual double-blind placebo-controlled trials, LINZESS 290 mcg did not consistently offer additional clinically meaningful treatment benefit over placebo than that observed with the LINZESS 145 mcg dose. Therefore, the 145 mcg dose is the recommended dose. Only the data for the approved 145 mcg dose of LINZESS are presented in Table 6 In Trials 3 and 4, the proportion of patients who were CSBM responders was statistically significantly greater with the LINZESS 145 mcg dose than with placebo Table 6: Efficity Responder Rates in Two Placebo-Controlled Trials of Adults with CIC (Trials 3 and 4): At Least 9 Out of 12 Weeks CSBM frequency reached maximum level during week 1 and was also demonstrated over the remainder of the 12-week treatment period in Trial 3 and Trial 4. For the mean change from baseline in CSBM frequency at week 12, the difference between placebo and LINZESS was approximately 1.5 CSBMs. On average, patients who received LINZESS across the 2 trials had significantly greater improvements compared with patients receiving placebo in stool frequency (CSBMs/week and SBMs/week), and stool consistency (as measured by the BSFS)

Linaclotide (LINZESS) is effective in treating severe constipation, as evidenced by the significant increase in CSBM frequency and improvement in stool consistency compared to placebo in clinical trials 2 and 2.

• The recommended dose is 145 mcg once daily.
• Key benefits of linaclotide include:
  • Increased CSBM frequency
  • Improved stool consistency
  • Reduced straining with bowel movements
• Linaclotide has been shown to be effective in patients with Chronic Idiopathic Constipation (CIC) and Irritable Bowel Syndrome with Constipation (IBS-C).

From the Research

Definition and Prevalence of Severe Constipation

• Severe constipation is a common clinical problem, with chronic constipation affecting up to 27% of the population in Western countries 3
• It is estimated that up to 24% of adults experience chronic constipation, with symptoms occurring in up to 50% of nursing home residents 4, 5

Management of Severe Constipation

• Initial management of chronic constipation should include lifestyle maneuvers, such as increased fiber and fluid intake, and scheduled toileting after meals 6, 4, 5, 7
• Additional fiber intake in the form of polycarbophil, methylcellulose, or psyllium may improve symptoms, but should be slowly increased over several weeks to decrease adverse effects 4
• Osmotic or stimulant laxatives, such as polyethylene glycol, are indicated if lifestyle changes are insufficient 6, 4, 5
• Prokinetics and secretagogues, such as lubiprostone, should be restricted to those not responding to basic treatment 3, 5
• Biofeedback therapy is effective in patients with dyssynergic defecation, and rectally administered laxatives or transanal irrigation may be attempted in patients with other evacuation disorders 5

Treatment Options for Severe Constipation

• Lubiprostone has been approved by the US Food and Drug Administration (FDA) for the treatment of chronic-idiopathic constipation and is effective in inducing peristalsis and laxation without stimulating gastrointestinal smooth muscle 3
• Linaclotide is also an effective treatment option for chronic constipation, and may be used in patients who do not respond to other treatments 6, 4
• Peripherally acting mu-opioid antagonists are effective for opioid-induced constipation, but are expensive 4
• Surgery is restricted to the minority of patients with very severe symptoms not responding to conservative treatment 5