Rectal Stricture: Etiology and Management

Definition

A rectal stricture, or stenosis, is a pathologic narrowing or constriction involving the lumen of the rectum. This narrowing can be the result of an intrinsic process that is occurring within the lumen or wall of the rectum, or it can be secondary to an extrinsic process compressing the rectum. A “clinically relevant” rectal stricture is one that is symptomatic and not easily defined by measurement of the diameter. However, the condition frequently has been illustrated in terms of the inability to traverse the affected cross-section of rectum with either a rigid proctoscope (12 mm diameter) or a rigid sigmoidoscope (19 mm diameter).

Presentation and Diagnosis

Symptomatic rectal strictures cause obstructive symptoms such as a gradual change in stool caliber or consistency, anorectal bleeding, tenesmus, or abdominal distention and discomfort that is often exacerbated by eating. Some symptomatic rectal strictures that are not treated will eventually cause a complete large bowel obstruction, especially those associated with inflammatory bowel disease (IBD), malignancy, and radiation-induced proctitis.

The diagnosis of a rectal stricture is based on history, physical examination, and, occasionally, imaging findings. The degree of a stenosis is best imaged with a water-soluble contrast enema. Computed tomography and magnetic resonance imaging, with or without rectal contrast enhancement, can be helpful in assessing other segments of the alimentary tract or the peritoneal cavity for conditions such as IBD and cancer.