Solitary rectal ulcer syndrome

Last updated

Solitary rectal ulcer syndrome or SRUS is a chronic, benign disorder of the rectal mucosa (the lining of the rectum). [1] It commonly occurs with varying degrees of rectal prolapse. The condition is thought to be caused by different factors, such as long term constipation, straining during defecation, and dyssynergic defecation. Treatment is by normalization of bowel habits, biofeedback, and other conservative measures. In more severe cases various surgical procedures may be indicated. The condition is relatively rare, affecting approximately 1 in 100,000 people per year. It affects mainly adults aged 30–50. Females are affected slightly more often than males. The disorder can be confused clinically with rectal cancer or other conditions such as inflammatory bowel disease, even when a biopsy is done. [2]

Contents

Signs and symptoms

The signs and symptoms are variable, and in up to 25% of patients there may be no symptoms. [3] The most common symptoms and signs are bleeding, which can vary from minor to severe, rectal prolapse and incomplete evacuation (35%-76% of cases). [4] According to one report, constipation is present in about 55% of cases, but diarrhea is present in 20%–40% of cases. [1] Reported symptoms are:

Causes

The exact cause is unclear and the condition is not fully understood. [3] There are thought to be multiple factors which simultaneously cause the condition. [3] Long term injury to the rectal mucosa and ischemic trauma are thought to be the main mechanisms. [5] In a report of 36 patients with SRUS, the underlying cause was internal prolapse (intussusception) in 20 patients, external rectal prolapse in 14 patients, and dyssynergic defecation (anismus) in 2 patients. [7]

Direct trauma

Self-digitation is when patients experiencing constipation resort to inserting a finger into the rectum in order to "hook out" fecal pellets, or to apply pressure to an obstructing lesion (see: obstructed defecation). The rectal mucosa is fragile and vulnerable to trauma when such manoeuvres are performed chronically. It is thought that this self-induced trauma is one possible mechanism of SRUS. [1] However, since sometimes the location of SRUS lesion(s) is much further than a finger could reach means that this cannot be the only cause. [5] In constipation, the stools may be very hard and this is another possible mechanism of trauma. [1]

Excessive straining: chronic constipation, dyssynergic defecation

People with constipation or certain anatomical anomalies are more likely to end up using excessive straining during defecation attempts. [5] Prolonged straining may cause direct trauma to the rectal mucosa. [5] Most patients with SRUS have dyssynergic defecation (previously termed anismus). [8] This is a failure of relaxation (or paradoxical contraction) of the puborectalis muscle during defecation attempts. This pelvic floor muscle is normally supposed to relax, thereby straightening the anorectal angle and allowing rectal contents to be evacuated. Dyssynergic defecation causes high pressure in the rectum and in the anal canal, [1] which causes lengthening [1] and compression of the rectal tissues, which in turn leads to ischema of the mucosa. [8] There is also a shearing movement of the rectum against the pelvic floor muscles. [8] In the long term this leads to repeated mucosal damage. [8] Inappropriate contraction of puborectalis in the squatting position causes traumatic compression of the rectal wall against the anal canal. [5] Also, it is reported that individuals with SRUS have not only increased pressure when squeezing, but also higher resting pressure compared to normal controls. [5]

Rectal prolapse and ischemic injury

SRUS is usually accompanied by prolapse (e.g. external prolapse or rectoanal intussusception/internal prolapse) or other pelvic-floor disorders. [1] [7] This is association is common, but not always present. [9] Some state that if SRUS is not treated, it would always tend to progress to rectal prolapse. [5] The relationship of SRUS with rectal prolapse and rectal cystitis profunda is debated. [8] Some see SRUS and prolapse as synonymous, while others see them as separate entities, [8] and state that they do not share the same physiology. [6] For example the mucosal changes that occur with external rectal prolapse can be separated from the mucosal changes seen in SRUS. [6]

The excessive pressure caused by straining (dyssynergic defecation and constipation) may in the long term lead to development of the spectrum of rectal prolapse conditions (mucosal versus full-thickness prolapse, internal versus external rectal prolapse). [5] These conditions create chronic vascular trauma (ischemia/hypoperfusion) in the rectal mucosa, [1] which predisposes it to ulceration, [8] and pressure necrosis. [4] Even the initial small areas of an intussusception can lead to vascular injury and reduce blood supply to the region. [5] This is the first stage of ulcer development. [5]

Other factors

Psychological factors are also thought to be involved, since patients with SRUS sometimes psychological disorders such as obsessive-compulsive disorder. [1] Also, some unknown factors may also be involved such as hormonal factors related to pregnancy. [5] Other possible factors are rectal hypersensitivity, [4] and impaired rectal evacuation of stool. [9]

Diagnosis

Diagnosis is difficult because of rarity of the condition and variability of the symptoms and the histologic appearance. [1] [5] The condition is sometimes misdiagnosed. [1] Diagnosis may be delayed by many years as a result. [4]

Differential diagnosis

The differential diagnosis is as follows:

Investigations

Investigations used in the diagnosis of SRUS include defecography, endoanal ultrasound colonoscopy and histological examination of a biopsy. [3]

Colonoscopy

The macroscopic appearance of SRUS is very variable. [8] Indeed, the condition has been referred to as “the three-lies disease”, [4] because the name of the condition is sometimes misleading. In reality, there may be more than one lesion, which may not be ulcerative, [10] and the condition may appear in different parts of the gastrointestinal tract (i.e. other than the rectum). [3]

Classically, there is a solitary ulcer. But only 20% of patients have a single ulcer whereas in other cases there may be multiple lesions. [6] The size of the ulcers is usually 0.5–4 cm. [5] The lesion is most often located on the anterior (front) or lateral (side) rectal wall, centered on a rectal fold, [1] usually 10 cm from the anal verge. [8] Less commonly there may be ulcers in the anal canal or even in the sigmoid colon. [5] The nature of the tissue changes can vary from simple erythema (redness) / hyperaemia (increased blood flow) of the mucosa 18% of cases, [1] to a chronic-appearing, small shallow ulcer with nodular margins and a white or sloughing base. [8] [1] In up to 33% of cases there is no ulceration but instead one or more well-developed polyps or mass lesions. [8] [5] There is usually mild proctitis (inflammation of the rectal mucosa) surrounding the ulcer. [2]

Defecography

Conventional defecography or magnetic resonance defecography may be used. [1] Between 50-100% of patients with SRUS will have abnormal defecography results. [5] Defecography findings in SRUS may include:

  • Evidence of dyssynergic defecation (anismus), [8] 82% of patients with SRUS had dssynergic defecation in one report. [1]
  • Rectal intussusception (the most common finding in one report). [5]
  • Anterior (front) or posterior (back) rectocele. [5]
  • Prolonged retention of contrast media. [5]
  • Megarectum. [5]

Endoanal ultrasound

Endoanal ultrasound can determine the depth of the ulcer and structure of the external and internal anal sphincters. [8] Endoanal ultrasound findings in SRUS include:

Biopsy

The histological appearance is as follows:

  • Segmental and superficial (shallow) ulceration. [5] [1]
  • Obliteration of the lamina propria with fibromuscular / collagen infiltration. [8] [5] This feature differentiates SRUS from inflammatory bowel disease, and is the landmark diagnostic feature for SRUS.
  • Hypertrophy and disruption of muscularis mucosa layer. [8] [5]
  • Hyperplasia and distortion of crypt structure. [5] [1]
  • Chronic inflammatory cell infiltration. [1]
  • No evidence of malignancy [8] (unless as very rarely happens the two conditions occur together). [5]

If the biopsy includes polypoid lesions, there are villiform structures visible. [5] Gland entrapment in the submucosa is sometimes seen, which is termed colitis cystica profunda. [5]

Management

Treatment of SRUS is difficult and there is a lack of evidence-based guidelines for treatment of SRUS. [4] The treatment is based on the pathophysiology of SRUS, [5] and the main aim is restoration of a normal pattern of defecation. [1] The exact treatment depends on the severity of the symptoms, the severity/type of SRUS and whether rectal prolapse is present or absent. [5]

Conservative measures are the first line treatment for patients with no symptoms, or only mild to moderate symptoms, and who have no significant anatomical defect. [1] Conservative measures by themselves may improve symptoms and prevent the condition getting worse. [1] Where conservative measures fail, or with severe disease and symptoms, or with significant anatomical defects, surgical options may be indicated. [5] [1] Improvement in symptoms does not always equate to healing of the ulcer as seen on endoscopy. [5]

Conservative (non-surgical)

Conservative management is focussed on education of the patient and behaviour modification. Where indicated, conservative management may also involve treatment of psychological problems, [5] and avoidance of anal-receptive sex (to prevent trauma to the rectum). [8]

Modification of bowel habit

  • Regular bathroom visits, [8] for a limited period of time. [5]
  • Avoidance of excessive straining. This can improve symptoms in up to 67% of cases and allow some degree of healing of the ulcer in about 30% of cases. [1]
  • Use of a stool to elevate the legs during defecation, [6] thereby straightening the anorectal angle and allowing for less effort during defecation. Alternatively, a squatting position can be used.
  • Avoidance of any kind of rectal manipulation (digitation, enemas, suppositories). [1]

Dietary measures

Biofeedback

Biofeedback targets pelvic floor behaviours and enables a reprogramming of autonomic nerologic pathways associated with defecation. [8] The treatment is particularly helpful for dyssynergic defecation. Research studies have shown that there is improved blood flow to the rectal mucosa after biofeedback therapy. [1] The overall rate of complete resolution of both symptoms and ulceration varies at 50-75%. [8] Stool frequency and straining effort decrease after this treatment. [1] In about 56% of cases biofeedback treatment stops rectal bleeding. [1] Some patients are able to cease relying on digitation. [1] Biofeedback is more effective in children with SRUS compared to adults. [1]

Topical agents

Several different topical treatments (i.e. substances applied directly to the ulcer) have been reported, with variable outcomes. [1] They are usually administered by enema and may be helpful for short term management of acute symptoms in SRUS. [8] They are thought to work by reducing inflammation and physically forming a barrier over the surface of the ulcer to protect it from irritants and allowing it to heal. [4] [5] However the long term efficacy is unknown. According to a systematic review, 57% of SRUS patients receiving medical treatment had resolution of ulceration. [4] Topical agents which have been used for SRUS include:

Surgery

Surgery may be indicated for severe cases of SRUS (either severe symptoms, severe ulceration, or significant associated anatomical defect such as prolapse), or when conservative measures fail. [8] [5] Some authors state that most patients do not benefit from surgery. [5] Overall, up to 33% of SRUS patients end up requiring surgery. [8] A systematic review reported that SRUS improved in 77% of patients who underwent any type of surgery, [6] however 52% of cases developed a later recurrence of the condition. [6] It has been suggested that any treatment which only addresses the ulcer without correcting the underlying causes will typically lead to recurrence. [8]

There are multiple different surgical procedures which have been reported for SRUS, [5] including:

Local therapies

Various local treatments for SRUS have been reported. According to one report, such measures have generally unfavorable results, and sometimes the ulcer returns deeper and larger than before the treatment. [8]

  • Injection of steroid 100 mg diluted in 10 ml water into the rectal wall around the ulcer. [6]
  • Argon plasma coagulation (APC). This procedure uses high frequency monopolar current directed by ionised argon gas to coagulate tissues and mucosal ulcers, aiming to promote healing through re-epithelializion. [6]
  • Sclerotherapy: injection into the submucosal layer or retro rectal space with 5% phenol, 30% hypertonic saline or 25% glucose and perianal cerclage. [5]
  • Human fibrin glue sealant applied endoscopically. [5] [8]
  • Injection of botulinum toxin injection into the external anal sphincter. [5] [8]

Local excision

Excision (removal) of the ulcer and suturing the resulting defect with surrounding healthy mucosa has been reported. However, the may not be any long-term benefit. [8] Ulcers in the upper part of the rectum may be accessible to local excision using a transanal minimally invasive approach (TAMIS). [8] Excision with neodymium yttrium-aluminiumgarnet laser has also been reported. [6]

Rectopexy

Rectopexy is a surgery for rectal prolapse. [3] A newer version of the procedure is termed ventral mesh rectopexy, which has also been used for SRUS. [11] It may be performed with or without anterior resection (removal of a portion of the front wall of the rectum). [9] It may be used with or without mesh to reinforce the anterior rectal wall. [8] It can be done as an open procedure or with a laparoscopic abdominal approach. [8] Some authors state rectopexy is suitable in highly select cases, [9] while others say it is the procedure of choice, [7] since it directly addresses the most likely cause. [8] There is also more evidence to support the use of rectopexy in SRUS compared to other surgical procedures. [8] Approximately 55-83% of patients with SRUS get reduced symptoms after rectopexy, [8] and these benefits appear to be long term. [3]

Other options

The following "last resort" surgical procedures (which may have significant consequences) have been reported in severe, persistent or recurrent cases of SRUS:

Epidemiology

The condition is relatively rare, but the exact prevalence is not known. [3] Prevalence has been estimated as 1 in 100,000 people per year. [3] SRUS can occur at any age, but it is most common in adults aged between 30-50. [3] Males and females are affected almost equally. [3] or slightly more in females. [1]

Misdiagnosis as inflammatory bowel disease (IBD) or rectal polyps may hide the true prevalence of SRUS. [3]

Related Research Articles

<span class="mw-page-title-main">Defecation</span> Expulsion of feces from the digestive tract via the anus

Defecation follows digestion, and is a necessary process by which organisms eliminate a solid, semisolid, or liquid waste material known as feces from the digestive tract via the anus. The act has a variety of names ranging from the common, like pooping or crapping, to the technical, e.g. bowel movement, to the obscene (shitting), to the euphemistic, to the juvenile. The topic, usually avoided in polite company, can become the basis for some potty humor.

<span class="mw-page-title-main">Constipation</span> Bowel dysfunction

Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement. Complications from constipation may include hemorrhoids, anal fissure or fecal impaction. The normal frequency of bowel movements in adults is between three per day and three per week. Babies often have three to four bowel movements per day while young children typically have two to three per day.

<span class="mw-page-title-main">Fecal incontinence</span> Inability to refrain from defecation

Fecal incontinence (FI), or in some forms encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents, both liquid stool elements and mucus, or solid feces. When this loss includes flatus (gas), it is referred to as anal incontinence. FI is a sign or a symptom, not a diagnosis. Incontinence can result from different causes and might occur with either constipation or diarrhea. Continence is maintained by several interrelated factors, including the anal sampling mechanism, and incontinence usually results from a deficiency of multiple mechanisms. The most common causes are thought to be immediate or delayed damage from childbirth, complications from prior anorectal surgery, altered bowel habits. An estimated 2.2% of community-dwelling adults are affected. However, reported prevalence figures vary. A prevalence of 8.39% among non-institutionalized U.S adults between 2005 and 2010 has been reported, and among institutionalized elders figures come close to 50%.

<span class="mw-page-title-main">Hematochezia</span> Medical condition

Haematochezia is the passage of fresh blood through the anus path, usually in or with stools. The term is from Greek αἷμα ("blood") and χέζειν. Hematochezia is commonly associated with lower gastrointestinal bleeding, but may also occur from a brisk upper gastrointestinal bleed. The difference between hematochezia and rectorrhagia is that, in the latter, rectal bleeding is not associated with defecation; instead, it is associated with expulsion of fresh bright red blood without stools. The phrase bright red blood per rectum is associated with hematochezia and rectorrhagia.

<span class="mw-page-title-main">Rectal prolapse</span> Medical condition

A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depending on whether the prolapsed section is visible externally, and whether the full or only partial thickness of the rectal wall is involved.

<span class="mw-page-title-main">Rectocele</span> Bulging of the rectum into the vaginal wall

In gynecology, a rectocele or posterior vaginal wall prolapse results when the rectum bulges (herniates) into the vagina. Two common causes of this defect are childbirth and hysterectomy. Rectocele also tends to occur with other forms of pelvic organ prolapse, such as enterocele, sigmoidocele and cystocele.

<span class="mw-page-title-main">Colorectal surgery</span> Field in medicine for disabilities in the rectum

Colorectal surgery is a field in medicine dealing with disorders of the rectum, anus, and colon. The field is also known as proctology, but this term is now used infrequently within medicine and is most often employed to identify practices relating to the anus and rectum in particular. The word proctology is derived from the Greek words πρωκτός proktos, meaning "anus" or "hindparts", and -λογία -logia, meaning "science" or "study".

Rectal tenesmus is a feeling of incomplete defecation. It is the sensation of inability or difficulty to empty the bowel at defecation, even if the bowel contents have already been evacuated. Tenesmus indicates the feeling of a residue, and is not always correlated with the actual presence of residual fecal matter in the rectum. It is frequently painful and may be accompanied by involuntary straining and other gastrointestinal symptoms. Tenesmus has both a nociceptive and a neuropathic component.

In medicine, the ileal pouch–anal anastomosis (IPAA), also known as restorative proctocolectomy (RPC), ileal-anal reservoir (IAR), an ileo-anal pouch, ileal-anal pullthrough, or sometimes referred to as a J-pouch, S-pouch, W-pouch, or a pelvic pouch, is an anastomosis of a reservoir pouch made from ileum to the anus, bypassing the former site of the colon in cases where the colon and rectum have been removed. The pouch retains and restores functionality of the anus, with stools passed under voluntary control of the person, preventing fecal incontinence and serving as an alternative to a total proctocolectomy with ileostomy.

<span class="mw-page-title-main">Aphthous stomatitis</span> Common condition of mouth ulcers

Aphthous stomatitis, or recurrent aphthous stomatitis (RAS), is a common condition characterized by the repeated formation of benign and non-contagious mouth ulcers (aphthae) in otherwise healthy individuals. The informal term canker sore is also used, mainly in North America, although it may also refer to other types of mouth ulcers. The cause is not completely understood but involves a T cell-mediated immune response triggered by a variety of factors which may include nutritional deficiencies, local trauma, stress, hormonal influences, allergies, genetic predisposition, certain foods, dehydration, some food additives, or some hygienic chemical additives like SDS.

Proctitis is an inflammation of the anus and the lining of the rectum, affecting only the last 6 inches of the rectum.

<span class="mw-page-title-main">Stapled hemorrhoidopexy</span>

Stapled hemorrhoidopexy is a surgical procedure that involves the cutting and removal of anal hemorrhoidal vascular cushion, whose function is to help to seal stools and create continence. Procedure also removes abnormally enlarged hemorrhoidal tissue, followed by the repositioning of the remaining hemorrhoidal tissue back to its normal anatomic position. Severe cases of hemorrhoidal prolapse will normally require surgery. Newer surgical procedures include stapled transanal rectal resection (STARR) and procedure for prolapse and hemorrhoids (PPH). Both STARR and PPH are contraindicated in persons with either enterocele or anismus.

<span class="mw-page-title-main">Defecography</span> Visualisation of the mechanics of a patients defecation

Defecography is a type of medical radiological imaging in which the mechanics of a patient's defecation are visualized in real time using a fluoroscope. The anatomy and function of the anorectum and pelvic floor can be dynamically studied at various stages during defecation.

<span class="mw-page-title-main">Rectum</span> Final portion of the large intestine

The rectum is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. The adult human rectum is about 12 centimetres (4.7 in) long, and begins at the rectosigmoid junction at the level of the third sacral vertebra or the sacral promontory depending upon what definition is used. Its diameter is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. It terminates at the level of the anorectal ring or the dentate line, again depending upon which definition is used. In humans, the rectum is followed by the anal canal which is about 4 centimetres (1.6 in) long, before the gastrointestinal tract terminates at the anal verge. The word rectum comes from the Latin rectumintestinum, meaning straight intestine.

<span class="mw-page-title-main">Anorectal manometry</span> Medical functional test of the anus and rectum

Anorectal manometry (ARM) is a medical test used to measure pressures in the anus and rectum and to assess their function. The test is performed by inserting a catheter, that contains a probe embedded with pressure sensors, through the anus and into the rectum. Patients may be asked to perform certain maneuvers, such as coughing or attempting to defecate, to assess for pressure changes. Anorectal manometry is a safe and low risk procedure.

Rectal discharge is intermittent or continuous expression of liquid from the anus. Normal rectal mucus is needed for proper excretion of waste. Otherwise, this is closely related to types of fecal incontinence but the term rectal discharge does not necessarily imply degrees of incontinence. Types of fecal incontinence that produce a liquid leakage could be thought of as a type of rectal discharge.

<span class="mw-page-title-main">Anismus</span> Medical condition

Anismus or dyssynergic defecation is the failure of normal relaxation of pelvic floor muscles during attempted defecation. It can occur in both children and adults, and in both men and women. It can be caused by physical defects or it can occur for other reasons or unknown reasons. Anismus that has a behavioral cause could be viewed as having similarities with parcopresis, or psychogenic fecal retention.

Obstructed defecation syndrome is a major cause of functional constipation, of which it is considered a subtype. It is characterized by difficult and/or incomplete emptying of the rectum with or without an actual reduction in the number of bowel movements per week. Normal definitions of functional constipation include infrequent bowel movements and hard stools. In contrast, ODS may occur with frequent bowel movements and even with soft stools, and the colonic transit time may be normal, but delayed in the rectum and sigmoid colon.

Descending perineum syndrome refers to a condition where the perineum "balloons" several centimeters below the bony outlet of the pelvis during strain, although this descent may happen without straining. The syndrome was first described in 1966 by Parks et al.

In fecal incontinence (FI), surgery may be carried out if conservative measures alone are not sufficient to control symptoms. There are many surgical options described for FI, and they can be considered in 4 general groups.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Alejandra, A-B; José María, R-T; Enrique, CA (1 January 2019). "18 - Solitary Rectal Ulcer Syndrome". Anorectal Disorders. Academic Press. pp. 227–236. ISBN   978-0-12-815346-8.
  2. 1 2 Herold A, Lehur PA, Matzel KE, O'Connell PR (2017). European Manual of Medicine: Coloproctology (Second ed.). Berlin, Germany. ISBN   978-3-662-53210-2.{{cite book}}: CS1 maint: location missing publisher (link)
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Forootan, M; Darvishi, M (May 2018). "Solitary rectal ulcer syndrome: A systematic review". Medicine. 97 (18): e0565. doi:10.1097/MD.0000000000010565. PMC   6392642 . PMID   29718850.
  4. 1 2 3 4 5 6 7 8 9 10 Qari, Y; Mosli, M (January 2020). "A systematic review and meta-analysis of the efficacy of medical treatments for the management of solitary rectal ulcer syndrome". Saudi Journal of Gastroenterology. 26 (1): 4–12. doi: 10.4103/sjg.SJG_213_19 . PMC   7045767 . PMID   31898642.
  5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 Sadeghi, A; Biglari, M; Forootan, M; Adibi, P (July 2019). "Solitary Rectal Ulcer Syndrome: A Narrative Review". Middle East Journal of Digestive Diseases. 11 (3): 129–134. doi:10.15171/mejdd.2019.138. PMC   6819965 . PMID   31687110.
  6. 1 2 3 4 5 6 7 8 9 10 11 12 Gouriou, C; Chambaz, M; Ropert, A; Bouguen, G; Desfourneaux, V; Siproudhis, L; Brochard, C (December 2018). "A systematic literature review on solitary rectal ulcer syndrome: is there a therapeutic consensus in 2018?". International Journal of Colorectal Disease. 33 (12): 1647–1655. doi:10.1007/s00384-018-3162-z. PMID   30206681. S2CID   52187439.
  7. 1 2 3 George B, Guy R, Jones O, Vogel J (2 May 2016). Colorectal Surgery: Clinical Care and Management. Chichester, West Sussex, UK: John Wiley & Sons. ISBN   978-1-118-67478-9.
  8. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 Kuckelman J; Johnson EK (2019). "Solitary Rectal Ulcer Syndrome". Chapter in: Clinical algorithms in general surgery: a practical guide. Cham: Springer. pp. 269–274. ISBN   9783319984971.
  9. 1 2 3 4 Rao, SSC; Tetangco, EP (August 2020). "Anorectal Disorders: An Update". Journal of Clinical Gastroenterology. 54 (7): 606–613. doi:10.1097/MCG.0000000000001348. PMID   32692116. S2CID   220670975.
  10. Kumagai, H; Yokoyama, K; Sunada, K; Yamagata, T (June 2021). "Solitary rectal ulcer syndrome: A Misleading term". Pediatrics International. 63 (6): 739–740. doi:10.1111/ped.14587. PMID   34142735. S2CID   235463337.
  11. Schlachta, CM; Sylla, P (20 February 2018). Current Common Dilemmas in Colorectal Surgery. Springer. ISBN   978-3-319-70117-2.