The anorectal ring is easy to identify when patients are asked to squeeze during digital rectal examination.
[3] This is a line formed by the lower ends of the anal columns and represents the embryological junction between the hindgut and the proctodeum.
This may be the case with malignant strictures, and the condition may be a medical emergency which requires urgent treatment in order to avoid serious complications such as bowel perforation.
Causes of benign strictures include: Acute bowel obstruction is a common presenting manifestation of colorectal cancer which is locally advanced.
[9] According to one review of a total of 730 cases, those which formed after anastomosis represented 74% of all reported benign rectal strictures.
[2] The next most common cause of benign rectal stricture was inflammatory bowel disease, accounting for 20% of all cases.
[2] However, a Cochrane review found no significant difference in the rate of rectal stricture between hand sewn and stapled ileocolic anastomosis (usually performed after right‐sided colon cancer and Crohn's disease).
[13] Thermal burns are possible if hot water enemas are attempted by patients or practitioners of alternative medicine in the belief that they will provide a stronger stimulus for evacuation of stool.
Such burns may be treated with bowel resting, antibiotics, stool softeners, liquid diet and steroid suppository to reduce inflammation.
[11] The rectum is very close to the prostate in males and the uterus and cervix in females, and therefore it frequently receives radiation during radiotherapy for cancers in the pelvic region.
[7] Such rectal strictures are usually located in the proximal rectum, and are one of the most common features of late radiation damage.
[14] Post-irradiation strictures may cause symptoms such as diarrhea, tenesmus, narrow feces, abdominal pain, and vomiting.
[7] The risk of intestinal obstruction due to strictures in patients receiving radiotherapy in the pelvis is reported as 1–15%.
[7] Sexually transmitted infections may sometimes cause rectal strictures in persons who engage in anoreceptive sex.
The condition is similar to Crohn's disease with rectal stricture formation (eventually), bowel perforation and fistulae.
[2] If a foreign body becomes stuck there is reactive inflammation and fibrosis, which eventually may lead to the formation of a stricture.
For example, endoscopic submucosal dissection, which is a minimally invasive treatment for colorectal cancer, may rarely cause development of a rectal stricture.
How a rectal stricture is treated depends on the exact cause, the distance from the anal verge, the degree of narrowing, the severity of symptoms, and the health of the patient.
[6] Healing of rectal strictures in inflammatory bowel disease with TNF inhibitor occurs in 59% of cases.
[16][1][2] Sometimes the patient can be shown how to perform this dilation at home, but this is may be difficult for them, and rarely gives good long term results.
[2] In rectal strictures in the context of Crohn's disease, the long-term success rate of balloon dilation is about 80%.
[11] Debulking of malignant strictures may be carried out with laser ablation or with argon beam plasma coagulation.
[18] Stents may be used as the definitive treatment of a stricture, or as a temporary measure to stabilize a patient with acute obstruction before another procedure is carried out.