Chronic proctalgia is a general term for chronic or recurring pain in the anal canal or rectum[3
]. Other names considered synonymous with chronic proctalgia are levator ani syndrome, puborectalis syndrome, chronic idiopathic perineal pain, pyriformis syndrome, and pelvic tension myalgia. Thiele, one of the first researchers to investigate this pain syndrome, called it coccygodynia, although he acknowledged that the pain was not in the coccyx[4
]. To provide greater consistency in the diagnosis and labeling of anorectal pain syndromes, the Rome III criteria[3
] define chronic proctalgia as chronic or recurrent rectal pain or aching lasting at least 20 min, in the absence of structural or systemic disease explanations for these symptoms[3
]. Pain duration of at least 20 min is a key feature since shorter episodes of pain are suggestive of proctalgia fugax, which is defined as a sudden, severe pain in the anorectal region lasting less than 20 min and then disappearing completely[3
]. Proctalgia fugax may recur, but episodes are rare. Proctalgia fugax is believed to have a different etiology to chronic proctalgia, although there is no consensus on what causes it. Its consideration is beyond the scope of this review, which is intended to deal with chronic unremitting diseases.
Chronic proctalgia is further divided by the Rome III criteria into two subtypes-levator ani syndrome (LAS) and unspecified functional anorectal pain-based on the presence or absence of a sensation of tenderness when the levator muscle is palpated during digital rectal examination. This classification updates the previous Rome II classification in which LAS was designated as “highly likely” if traction on the pelvic floor produced a report of tenderness and only “possible LAS” if no tenderness was elicited[5
]. Subgrouping patients with chronic proctalgia is consistent with clinical experience of different response to treatment, but distinct epidemiology and pathophysiology data are lacking[5
]. Therefore, data provided mostly refer to chronic proctalgia patients as a whole.
Chronic tension or spasm of the striated muscles of the pelvic floor is commonly assumed to be the pathophysiological basis for chronic proctalgia[3,5-7
], although there is no definitive evidence for this hypothesis. Inflammation of the levator or arcus tendon of the levator ani muscle has also been suggested as a cause of chronic proctalgia, since tenderness on palpation is most commonly found on the left side where the muscle inserts into the pubic ramus of the pelvis. However, contrary to this tendinitis hypothesis, local steroid injection has not been shown to be an effective treatment for chronic proctalgia[8
]. In retrospective studies, many patients reported prior pelvic surgery, anal surgery and even spinal surgery as significant in the development of their pain syndrome[6,9
]. Childbirth can be another precipitating factor[9
]. In addition, high rates of anxiety disorders, depression, and stress are frequently reported in chronic proctalgia, and may act as significant precipitating factors in some patients[6,10
Except for the exclusion of organic diseases, tests of anorectal physiology and imaging studies were traditionally considered to be of little diagnostic or prognostic value[11,12
]. Increased anal canal resting pressures tested by anorectal manometry were sometimes reported, but results were inconsistent. Grimaud and coworkers reported that LAS was associated with anal sphincter hypertonia and disordered defecation on dynamic proctography in a study of 12 patients, but this was not confirmed in a larger prospective study of 60 patients by Ger and coworkers[11,13
] . Ger et al[11
] reported that LAS was associated with paradoxical contraction of the pelvic floor muscles on straining as evidenced by anal electromyography or defecography. However, all these studies were potentially biased by small size, mixed patient population, and poor patient selection[3,5
]. In addition, a number of structural disorders (descending perineum, rectocele, mucosal prolapse and pelvic floor dyssyenrgia) have been reported in small studies[6,11-13
In a recent study, Hompes et al[14
] reported on 59 patients referred to a Pelvic Floor Clinic for chronic functional anorectal pain who were tested by means of defecating proctography, anorectal manometry, anal ultrasound, and in selected cases, rectal examination under anesthesia. The same diagnostic protocol was applied to 543 rectal prolapse patients complaining of obstructed defecation and to a control group of patients with fecal incontinence. In the control group with fecal incontinence, pain was reported in 50% of patients but was a non-dominant symptom. Anorectal manometry failed to show any difference among groups. Rectal morphology examinations demonstrated high grade internal rectal prolapse in 59% of pain patients, which was often associated with symptoms of obstructed defecation. The authors concluded that rectal prolapse commonly underlies chronic proctalgia, particularly when obstructed defecation is present. However, the severity of prolapse did not correlate with pain intensity, leaving pain pathophysiology unclear[14
]. In addition, chronic idiopathic rectal pain is sometimes reported as a complication of corrective surgery for rectal prolapse[14
An innovative pathophysiology explanation for chronic proctalgia was recently reported by our group in a large, prospective, randomized controlled trial comparing biofeedback, electrogalvanic stimulation (EGS), and digital massage of the levator muscles for the treatment of chronic proctalgia. In this study, 157 patients with chronic proctalgia (confirmed by Rome II criteria) were studied by anorectal manometry and a balloon evacuation test at baseline and again after 3 mo of treatment[2
]. Based on a priori exclusion criteria, patients reporting symptoms consistent with either irritable bowel syndrome or functional constipation were not enrolled in the study. In patients reporting tenderness on palpation of the levator muscles (Rome II: highly likely LAS, Rome III: LAS), physiologic features of dyssynergic defecation (i.e., paradoxical contraction or failure to relax the pelvic floor on straining) were seen in approximately 85% of subjects in the absence of symptoms of constipation. Conversely, in patients who denied tenderness when the levators were palpated during digital rectal examination, inability to relax pelvic floor muscles when straining was an uncommon finding (19%). Dyssynergic defecation was a strong predictor of successful treatment outcome. These observations led us to conclude that the physiologic mechanisms responsible for LAS and dyssynergic defecation are similar[2
This study also showed that the inability to relax pelvic floor muscles when straining to defecate may occur without symptoms of constipation, even though it is commonly assumed that dyssynergic defecation invariably results in obstructed defecation. Factors that interact with pelvic floor physiology to determine which symptoms develop-either pain or constipation-are left unanswered by our study and deserve further investigations. Also, we were not able to provide a physiological explanation for unspecified functional anorectal pain (i.e., anorectal pain without tenderness on digital palpation), which may represent a heterogeneous group of patients. Our study suggests, however, that adding a simple balloon evacuation test with a disposable Foley catheter to the diagnostic work up of chronic proctalgia patients enables one to select subjects that are more likely to benefit from pelvic floor rehabilitation.
Chronic proctalgia is often described by patients as a dull ache or pressure sensation in the rectum that is exacerbated by prolonged sitting and relieved by standing or lying down[3,5
]. This pain rarely occurs at night; rather, it usually begins in the morning and increases in severity throughout the day. The pain may be precipitated by long-distance car travelling, stress, sexual intercourse and defecation[6,7
]. During digital rectal examination, the examining finger is moved from the coccyx posteriorly to the symphysis pubis anteriorly[5,7
]. For unexplained reasons, tenderness is often non-symmetric, being greater on the left side than on the right[5
]. When performing digital rectal examination, the examiner should pause after inserting their finger into the rectum before applying traction on the levator muscles to avoid false positive results. In our experience, repeating the posterior traction on the levator muscle on the same exam is also useful to check for reproducibility and to avoid false positive results.
No single treatment has been reported to be consistently effective in chronic proctalgia[3,7
], and management can be a frustrating endeavor for both patients and physicians[11
]. The first-line treatment most commonly provided is reassurance that the pain is of benign origin and is not suggestive of malignancy[7,9
]. No data are available on the impact of reassurance, but education and counseling are often incorporated as a component of treatment.
Digital massage of the puborectalis sling, intended to relax tense muscles, was one of the first treatments proposed for chronic proctalgia[9
]. Massage of the puborectalis muscle should be performed in a firm manner with the affected side massaged up to 50 times, depending on the patient’s tolerance. Some claim that if the massage is not uncomfortable to the patient while being performed, it may not be effective[9
]. Massage of the levator ani muscle is rarely performed as the sole therapy, with the most common adjunctive treatments being hot sitz baths or a short-term course of oral Diazepam, both of which are assumed to have myorelaxant properties. Earlier open-label studies suggested that digital massage combined with hot sitz baths and/or Diazepam were effective for relieving pain in 68% of 316 chronic proctalgia patients[15
]. However, benefits seemed to fade away during long-term follow-up, and the addictive potential of Diazepam discourages long-term treatment[7
Electrogalvanic stimulation, traditionally used by physiatrists to treat muscle spasticity[9
], has also been advocated for the treatment of LAS when conservative therapy is ineffective. A low frequency oscillating current applied to the pelvic floor muscles through an anal probe, induces fasciculation and prolonged fatigue, which breaks the spastic cycle and may produce sustained symptom relief. Low frequency current has no thermal effect. No side effects have ever been reported other than mild worsening of pain on the first days of treatment. Sohn and coworkers were the first to test EGS in an open study of 80 chronic proctalgia patients[16
]. They recommended a pulse frequency of 80 cycles per second with the voltage being gradually increased from zero to the point of discomfort (250-300 Volts according to patient’s tolerance). Recommended treatment duration is one hour per day for 3 sessions in a ten-day period. In the Sohn study[16
], 91% of patients reported good to excellent pain relief from EGS in the short-term, but no long-term follow-up was reported. This high percentage of success was never replicated by subsequent open label studies, although approximately two-thirds of patients did report short-term pain relief. Treatment protocols varied widely in terms of number and duration of sessions. Authors claimed that non-responders showed features of psychology disturbances, but no evidence was provided on the issue. However, three additional studies that investigated the long-term benefits of EGS treatment in chronic proctalgia found that only 25%-38% of patients reported persistent pain improvement[17-19
Biofeedback treatment of LAS was first described in 1991 by Grimaud and coworkers[13
]. They treated 12 patients with biofeedback techniques focused on voluntary relaxation of external anal sphincter tone. Pain disappeared in all patients after a mean of eight sessions. Subsequent studies using biofeedback were not able to replicate these results, with success rates varying from 35% to 87.5%[6,11,19
]. All studies were small, none was controlled, and treatment modalities varied.
Botulinum Toxin A (BoTox A) was tested in a randomized controlled trial run in 12 patients, and no differences in rectal pain were observed between patients injected with active BoTox versus
those injected with saline[20
]. The average amount of time required to defecate a rectal balloon was actually increased after BoTox injection. The tendinitis (inflammation) hypothesis for chronic proctalgia was tested by steroid caudal block and by pelvic tender point injection of a mixture of Triamcinolone Acetonide and Lidocaine with negative results[8,11
]. Sacral nerve stimulation was also reported to be beneficial in an open study involving 27 chronic proctalgia patients. However, when benefits were assessed by intent to treat analysis, pain relief was reported in less than 50% of subjects[21
A major drawback in assessing the literature on chronic proctalgia treatment is the huge variation in inclusion criteria, outcome criteria, and follow-up intervals. Additional limitations are small sample sizes and lack of an appropriate control group. The few quasi-randomized studies had control groups that included subjects who received more than one treatment and patients not responding to a former therapy[7
]. To overcome these limitations, Chiarioni and coworkers recently reported a prospective, randomized controlled trial of 157 chronic proctalgia patients to investigate the comparative effectiveness of the 3 most commonly prescribed treatments: biofeedback to teach pelvic floor muscle relaxation, EGS, and digital massage of the levator muscles[2
]. A physiological assessment including manometry and balloon defecation was carried-out at baseline and at 1-3 mo follow-up. In addition, self-reported stool frequency was assessed at baseline and at 6-mo follow-up. The primary outcome was subjective reporting of adequate pain relief by the patient. Secondary outcomes included subjective pain improvement on an ordinal scale, number of days per month with rectal pain, and visual analog scale ratings of pain. According to Rome II criteria, proctalgia patients were subgrouped into highly likely LAS and possible LAS based on the presence or absence of levator tenderness at digital rectal exam, and randomization to treatment groups was stratified so that each treatment group contained a similar number of patients with a highly likely diagnosis of LAS.
At one-month follow-up, biofeedback was significantly more effective than EGS and massage by intent-to-treat analysis, with adequate relief of pain reported by 59.6% vs
28.3% for biofeedback, EGS, and massage, respectively. Benefits were maintained throughout follow-up (12 mo) and no side effects were reported with any treatment. When results were further investigated in subgroups of patients, no treatment was effective in possible LAS patients (Rome III unspecified functional anorectal pain). However, among patients with highly likely LAS (Rome III levator ani syndrome) adequate relief was reported by 87% for biofeedback, 45% for EGS and 22% for massage at 1 mo follow-up. Improvements were maintained for the whole follow-up. The superiority of biofeedback was supported by all the secondary outcome measures including number of days per month with pain, which decreased from 14.7 per month to 3.3 per month for biofeedback, 8.9 for EGS, and 13.3 for massage[2
Physiological measurements revealed that the mechanism for achieving adequate pain relief was an improvement in pelvic floor function from being unable to relax anal canal pressures on straining to being able to do so and/or an improvement on the balloon evacuation test from being unable to pass a 50 mL balloon to being able to do so[2
]. This interpretation of the mechanism of action was confirmed by a post-hoc analysis showing that 94.2% of those who improved pelvic floor dysfunction on one or both of these measures reported adequate pain relief, while only 13.6% of those who did not improve pelvic floor function reported positive therapy outcome regardless of the treatment provided. In addition, stool frequency increased from baseline to post-treatment in responders, even in the absence of a former complaint of constipation. This study led us to conclude that biofeedback is an effective treatment for LAS, and EGS is somewhat effective. However, the minority of proctalgia patients affected by unspecified functional anorectal pain are still left without a satisfactory treatment option. In this regard, depression and anxiety are both frequently reported in non-responsive proctalgia patients[6,10
]. Brain processing of pain may be altered in functional gastrointestinal disorders, but data in proctalgia patients are lacking[22
]. In addition, no trial has actually evaluated the effect of either psychotherapy intervention or psychotropic drugs in proctalgia patients. Finally, there is no evidence that surgery can help these severely disabled patients. Invasive interventions should be avoided in the absence of a clearer etiologic understanding of non-responsive proctalgia patients[3