mainly conservative. many such conservative (non surgical / medical) measures have been used to treat ods: biofeedback, also termed (pelvic floor rehabilitation). dietary measures, especially high fiber diet. bulking laxatives. rectal irrigation. transanal electrostimulation. yoga. psychotherapy. placing a stool or box under the feet to raise the legs to simulate squatting posture. diet dietary measures are frequently used for ods as the first line treatment. the aim is to improve stool texture. it has been recommended to avoid foods like chocolate, which increase stool viscosity, making it more difficult to pass stools. bulk-forming laxatives are also frequently used for ods. it is recommended to increase dietary fiber intake to 25-30 grams daily. this may be slowly increased up to a level of 50 grams per day. this is usually achieved with high-fiber cereal and fiber powder supplements such as psyllium, methylcellulose, polycarbophil, or wheat dextrin. however, fibre supplementation only fractionally increases gut transit and stool bulk. the effect may take several weeks to become apparent. other authors report that a high fiber diet rarely helps ods symptoms, and may make them worse. patients with ods are often advised to drink plenty of water. 1-2 liters of water per hour is recommended, especially in warmer climates or warmer weather. biofeedback / pelvic floor rehabilitation biofeedback is a learning strategy which is based on operant conditioning. the main goal is to improve abdominal and pelvic floor coordination. this is usually done by giving the patient visual or auditory feedback about muscular contraction during attempted defecation maneuvers, as well as verbal feedback about posture and diaphragmatic breathing. biofeedback can successfully treat abnormal contraction and relaxation of muscles in the anorectum during defecation. this enables normal peristalsis instead of abnormal contraction and retrograde of bowel contents. biofeedback is now one of the most popular treatments for ods, particularly because it is safe. it is most beneficial for patients with dyssynergic defecation. it is also used for rectal hyposensation. rectocele and recto-rectal intussusception can sometimes be treated by pelvic floor rehabilitation alone, as long as they have not been present for a long time. larger and more significant examples of these organic/anatomical disorders require surgery to correct since they because contributing causes to ods by themselves. regardless, this treatment seems to be beneficial both for patients with mild symptoms, and for those with severe symptoms which are unresponsive to other conservative measures and who are being considered for surgery. biofeedback has been shown to improve symptoms (improved frequency of bowel movements, reduced straining) and also reduce need for laxatives, and patients stop needing to self-digitate. researchers demonstrated that patients who had positive results with biofeedback had evidence of improved autonomic innervation of the colon, increased colonic transit time, and had increased quality of life scores. overall, biofeedback is reported to have about 70% success rate for pelvic floor dyssynergia (dyssynergic defecation). the success of biofeedback for patients with ods caused by mechanical defects is not well known. for patients who do not undergo biofeedback, simple pelvic floor and abdominal muscle relaxation exercises may also be useful to make evacuation easier. psychotherapy / psychological counselling psychological counselling is indicated for people with ods and depression and/or anxiety. psychological techniques (guided imagery and relaxation) have been combined with ultrasound-guided biofeedback. this "psycho-echo-biofeedback" approach was reported to be successful for 50% of patients after 2 years. irrigation variously termed hydrocolontherapy, lavage, retrograde large bowel irrigation, and rectal irrigation. this refers to the use of water to wash out the rectum. usually this is done with warm water (or normal saline), administered via a tube inserted into the anus. some authors report this treatment as effective and safe with no risk of side effects. self-administered enemas may however be abused, which can cause anorectal fibrosis and stricture, due to repeated microtrauma. the disadvantages of this treatment are mainly social stigma and inconvenience. the water and stool may take some time to fully evacuate, especially with patients with obstructed defecation. people with reduced muscular strength of the anal sphincter may encounter problems with later leakage of the water mixed with stool, which may bring similar, socially devastating problems as seen with fecal incontinence. overall this treatment may be dissatisfying to patients because of difficulty with cohabitation, travel, and work/study or leisure activities. transanal electrostimulation transanal electrostimulation is carried out at home with an anal probe and an electrostimulator. it is a treatment for pudendal nerve neuropathy and rectal hyposensation. another new treatment combines biofeedback with transanal electrostimulation. botox injections injection of 50-60 units of botulinum toxin a into the puborectalis muscle has been reported for anismus, and ods. the botulinum toxin is injected under ultrasound guidance into two sites on both sides of the puborectalis muscle. this procedure itself could be considered as minor surgery, although in the studies reporting this technique, patients were not sedated or given local anesthetic. short term cure rate was approximately 50%. another study reported 79% of patients had improved symptoms, and had broadening of the anorectal angle demonstrated on defecography. side effects are transient anal incontinence and hypotension. the effects of botox only last for about 3 months, meaning the procedure may only be temporary and it may have to be repeated. other measures anismus has been reported to be treated with yoga exercises. surgical surgical procedures can be considered in three groups: transvaginal, transabdominal and transanal; or as either manual techniques or stapling procedures. no surgical procedure has been demonstrated to be the best, and each has advantages and disadvantages. there are no widely accepted selection criteria for these surgical procedures. partial division of puborectalis muscle this transanal manual procedure aims to relax the tension of a hypertrophic (overdeveloped) puborectalis muscle. the partial division can be done laterally (on one side) or at the posterior midline (in the middle at the back of the muscle). there are some positive reports of this proceudre, which was said to be more effective compared to non surgical treatments such as biofeedback and botulinom toxin a injections. however other reports state that this method is disappointing, failing to improve ods symptoms for most patients. there is a high risk of fecal incontinence after this surgery and it is generally no longer recommended. ventral mesh rectopexy ventral mesh rectopexy has become popular for rectal prolapse, internal rectal prolapse and ods, especially in europe. it is also used for rectoceles, solitary rectal ulcer syndrome, and can be combined with procedures for vaginal prolapse, for example sacrocolpopexy. the predecessor of this procedure was sutured posterior rectopexy, in which the rectum was completely mobilized from the pelvic floor (i.e. including posterior and lateral surgical dissection of the rectum and sigmoid colon). this caused autonomic nerve damage resulting in constipation and obstructed defecation after the surgery. ventral rectopexy was developed in 2004 as a modification which would not destroy these nerves, since only the ventral/anterior surface (the front surface) is mobilized. a mesh is placed between the anterior wall of the rectum and the vagina. the mesh is then fixed to the sacrum, and the vaginal vault is fixed to the mesh. the mech reinforces the anterior rectal wall, which aims to prevent recurrence of enterocele, intussusception and rectocele. the pouch of douglas is lost in the process. as such, the aims of the procedure are surgical correction of prolapse of the posterior (rectum + sigmoid colon) and middle (female reproductive organs) pelvic compartments, elevation of the pelvic floor, and reinforcement of the vaginal septum / anterior rectal wall. the procedure is usually performed laparoscopically. the procedure reduces constipation and fecal incontinence in patients with rectal prolapse or rectal intussusception, and has a low rate of complications and recurrence. the procedure is able to correct multiple anatomical defects associated with vaginal and rectal prolapse, as well as improving function in terms of continence and defecation. prognosis ods generally has a benign prognosis, however it is distressing condition for patients. the condition may severely reduce quality of life, both socially and psychologically, and also reduce sexual well-being. symptoms persist for some patients despite conservative treatment, and dissatisfactory outcomes are frequently reported after surgery. epidemiology constipation as a general complaint is very common. the ods subtype is also known to be a common problem, but the exact reported epidemiological figures vary. it is estimated that approximately a third of patients complaining of constipation have the ods subtype, which is more than slow transit constipation. some reported or estimated figures include: 7% of adults. 10–20% of adults. 12–19% of north americans. up to 30% of the population. the prevalence is greater in older people of both sexes, especially women. overall, most patients with ods are females. some of the reasons for this female predilection are thought to be related to trauma from childbirth through vaginal delivery, menopausal tissue changes and hysterectomy. however, a not insignificant proportion of patients with ods are males or nulliparous females (i.e. have never given birth). notes "outlet obstruction" may also refer to disorders of the bladder (bladder outlet obstruction) or the stomach (gastric outlet obstruction). "outlet obstructive constipation" (ooc) appears to be the standardized term used in chinese publications. with the exception of substitution of the term "anismus", which is used in the ascrs consensus statement. many publications instead use the term "dyssynergic defecation", notably icd-11 and rome-iv. some authors have expressed disapproval of the continuned use of the term "anismus".