Abstract and Introduction
Background: Chronic constipation is a common, heterogeneous disorder with multiple symptoms and pathophysiological mechanisms. Patients are often referred to a gastroenterology provider after laxatives fail. However, there is limited knowledge of the spectrum and management of constipation disorders.
Aim: To discuss the latest understanding of the spectrum of constipation disorders, tools for identifying a pathophysiologic-based diagnosis in the specialist setting, treatment options and the patient's perspective of constipation.
Methods: Literature searches were conducted using PubMed for constipation diagnostic criteria, diagnostic tools and approved treatments. The authors provided insight from their own practices.
Results: Clinical assessment, stool diaries and Rome IV diagnostic criteria can facilitate diagnosis, evaluate severity and distinguish between IBS with constipation, chronic idiopathic constipation and dyssynergic defecation. Novel smartphone applications can help track constipation symptoms. Rectal examinations, anorectal manometry and balloon expulsion, assessments of neuromuscular function with colonic transit time and colonic manometry can provide mechanistic understanding of underlying pathophysiology. Treatments include lifestyle and diet changes, biofeedback therapy and pharmacological agents. Several classes of laxatives, as well as prokinetic and prosecretory agents, are available; here we describe their mechanisms of action, efficacy and side effects.
Conclusions: Constipation includes multiple overlapping subtypes identifiable using detailed history, current diagnostic tools and smartphone applications. Recognition of individual subtype(s) could pave the way for optimal, evidence-based treatments by a gastroenterology provider.
Constipation affects 15%-20% of the global population and carries a major health care burden.[1,2] The pathophysiology of chronic constipation is complex, exemplified by varying classifications. Patients often present with similar, overlapping symptoms.[3,4] Therefore, differentiation and appropriate classification of constipation types guides treatment selection.[4,5] Constipation is classified as primary or secondary, depending on the underlying cause.[3,4] Secondary constipation is associated with organic disease (eg, colonic stricture, mass or malignancy), medication use (eg, opioids, anti-cholinergic medications) or an underlying condition (eg, metabolic, thyroid or diabetic disorders), while primary constipation is a consequence of neuromuscular dysfunction of the colon or anorectal sensory-motor function.[3,6]
The complexity of primary constipation—and failure to respond to first-line treatments (eg, lifestyle changes and laxatives)—is why patients are referred to gastrointestinal (GI) specialists. Constipation disorders are sometimes difficult to manage, and patients are often dissatisfied with their treatment. Symptoms of constipation can be secondary to GI pathology, such as colonic strictures, advanced colorectal polyps or neoplasms, necessitating an age-appropriate colon cancer screening. Failure to address constipation disorders may result in symptom progression over time.
IBS with constipation (IBS-C), functional constipation or chronic idiopathic constipation (CIC) and defecatory disorders—especially dyssynergic defecation—comprise the most common spectrum of primary constipation disorders. IBS-C, CIC and dyssynergic defecation have overlapping symptoms. Another growing problem is opioid-induced constipation (OIC) and, although a secondary cause of constipation, significant new knowledge in the pathophysiology and treatment of OIC is helpful for GI specialists to consider when differentiating from a primary constipation diagnosis. Our purpose is to provide an up-to-date review on the spectrum of primary constipation disorders, focusing on understanding pathophysiology, diagnostic and clinical assessment tools, and pharmacologic and biofeedback therapies.
Aliment Pharmacol Ther. 2021;53(12):1250-1267. © 2021 Blackwell Publishing