{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T06:37:33Z","timestamp":1765607853598,"version":"3.48.0"},"reference-count":12,"publisher":"BMJ","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gut"],"published-print":{"date-parts":[[1991,6]]},"abstract":"<jats:p>Anal dilatation in response to gentle parting of the buttocks has been advocated as a sign of sexual abuse in children, but nothing is known of the physiology of this response or its existence in normal subjects, in patients with spinal disease, and in patients with a weak sphincter and whether it can be elicited after training. To answer these questions we investigated the effect of parting the buttocks on anal function. Combined anal manometry and electromyography was conducted in six normal subjects (five men, one woman, aged 19-53 years), in 18 patients with faecal incontinence (three men, 15 women, aged 30-80 years), and in seven paraplegic patients (six men, one woman, aged 25-36 years), in four of whom the posterior sacral roots had been cut. Parting the buttocks in normal subjects reduced the pressure in the anal canal from 102 (20) to 14 (3) cm H2O (mean (SEM), p less than 0.00001), but did not cause the anus to gape. This drop in pressure was associated with increased electrical activity in the external anal sphincter. Normal subjects could consciously relax the external anal sphincter and reduce the anal pressure but not so as to result in anal gaping during traction on the buttocks, even after anal dilatation. Stimulation of the anal lining by moving a probe in and out of the anal canal increased the activity of the external anal sphincter, raising anal pressures. Paraplegic patients who had lost conscious control of their external sphincters showed anal gaping when the buttocks were parted. A similar phenomenon was seen in patients with faecal incontinence who had weakness of the external anal sphincter, while incontinent patients with weakness of both sphincters showed anal gaping even at rest. Inasmuch as the results of our study can be applied to children, the data suggest that reflex anal dilatation should only be used to support a diagnosis of sexual abuse if sphincter function is otherwise normal and there is no evidence of cerebrospinal disease. Although our results do not support the notion that children could become so conditioned to repeated digital or penile penetration of the anus that they can cause the anus to gape when the buttocks are parted, neither do they exclude it.<\/jats:p>","DOI":"10.1136\/gut.32.6.670","type":"journal-article","created":{"date-parts":[[2007,9,18]],"date-time":"2007-09-18T17:41:31Z","timestamp":1190137291000},"page":"670-673","source":"Crossref","is-referenced-by-count":6,"title":["Reflex anal dilatation: effect of parting the buttocks on anal function in normal subjects and patients with anorectal and spinal disease."],"prefix":"10.1136","volume":"32","author":[{"given":"N W","family":"Read","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"W M","family":"Sun","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[1991,6,1]]},"reference":[{"key":"ref_1","first-page":"792","article-title":"Buggery in childhood - a common syndrome of child abuse","volume":"ii:","author":"Cj, Hobbs; JM, Wynne","year":"1986","unstructured":"Hobbs Cj, Wynne JM. Buggery in childhood - a common syndrome of child abuse. Lancet 1986; ii: 792-6.","journal-title":"Lancet"},{"key":"ref_2","first-page":"218","article-title":"Detecion of sexual abuse in children","volume":"ii:","author":"Wright, C.M.; Fraser, E.M.; Denman, M.; Duke, L.","year":"1987","unstructured":"Wright CM, Fraser EM, Denman M, Duke L. Detecion of sexual abuse in children. Lancet 1987; ii: 218.","journal-title":"Lancet"},{"key":"ref_3","first-page":"283","article-title":"Differential diagnosis in child sexual abuse","volume":"i:","author":"Hey, F.; Buchan, P.C.; Littlewood, J.M.; Hall, R.I.","year":"1987","unstructured":"Hey F, Buchan PC, Littlewood JM, Hall RI. Differential diagnosis in child sexual abuse. Lancet 1987; i: 283.","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"620","DOI":"10.1016\/S0140-6736(87)90252-2","article-title":"Anal appearances and child abuse","volume":"i:","author":"Clayden, G.","year":"1987","unstructured":"Clayden G. Anal appearances and child abuse. Lancet 1987; i: 620.","journal-title":"Lancet"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"842","DOI":"10.1016\/S0140-6736(87)91026-9","article-title":"Investigation of the sexually abused child","volume":"ii:","author":"Zeitlin, H.","year":"1987","unstructured":"Zeitlin H. Investigation of the sexually abused child. Lancet 1987; ii: 842-5.","journal-title":"Lancet"},{"key":"ref_6","first-page":"54","article-title":"Northern Regional Health Authority. Child sexual abuse: principles of good practice","volume":"39","year":"1988","unstructured":"Northern Regional Health Authority. Child sexual abuse: principles of good practice. Brj Hosp Med 1988; 39: 54-5, 57-62.","journal-title":"Brj Hosp Med"},{"key":"ref_7","first-page":"111","article-title":"The actions of parasympathetic and sympathetic nerves in human micturition, erection, and seminal emmission, and their restoration in paraplegic patients by","volume-title":"implanted electrical stimulators. Proc R Soc Lond 1988","volume":"235","author":"Brindly, G.B.","unstructured":"Brindly GB. The actions of parasympathetic and sympathetic nerves in human micturition, erection, and seminal emmission, and their restoration in paraplegic patients by implanted electrical stimulators. Proc R Soc Lond 1988; B235: 111-20."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1007\/BF01649702","article-title":"Anorectal function in normal human subjects: effect of gender","volume":"4","author":"Sun WM, Read NW","year":"1989","unstructured":"Sun WM, Read NW. Anorectal function in normal human subjects: effect of gender. Intj Colorect Dis 1989; 4: 188-96.","journal-title":"Intj Colorect Dis"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1007\/BF01648344","article-title":"Trowbridge EA, Read NW. An analysis of anal sphincter pressure and anal compliance in normal subjects","volume":"1","author":"Gibbons, C.P.; Bannister, J.J.","year":"1986","unstructured":"Gibbons CP, Bannister JJ, Trowbridge EA, Read NW. An analysis of anal sphincter pressure and anal compliance in normal subjects. Intj Colorectal Dis 1986; 1: 231-7.","journal-title":"Intj Colorectal Dis"},{"key":"ref_10","first-page":"277","article-title":"Studies on the reflex activity of the external sphincter ani in spinal man","volume":"1","author":"Melzak, J.; Porter, N.H.","year":"1964","unstructured":"Melzak J, Porter NH. Studies on the reflex activity of the external sphincter ani in spinal man. Paraplegia 1964; 1: 277-96.","journal-title":"Paraplegia"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1111\/j.1469-8986.1982.tb02599.x","article-title":"External anal sphincter response to rectal distension: learned response or reflex","volume":"19","author":"Whitehead, N.E.; Orr, W.C.; Engel, B.T.; Schuster, M.M.","year":"1982","unstructured":"Whitehead NE, Orr WC, Engel BT, Schuster MM. External anal sphincter response to rectal distension: learned response or reflex. Psychophysiology 1982; 19: 57-72.","journal-title":"Psychophysiology"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1007\/BF02563687","article-title":"Voluntary relaxation of the external anal sphincter","volume":"32","author":"Broden, G.; Dolk, A.; Frostell, C.; Wilsson, B.; Holmstrom, B.","year":"1989","unstructured":"Broden G, Dolk A, Frostell C, Wilsson B, Holmstrom B. Voluntary relaxation of the external anal sphincter. Dis Colon Rectum 1989; 32: 376-8.","journal-title":"Dis Colon Rectum"}],"container-title":["Gut"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/gut.32.6.670","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T06:34:28Z","timestamp":1765607668000},"score":1,"resource":{"primary":{"URL":"https:\/\/gut.bmj.com\/lookup\/doi\/10.1136\/gut.32.6.670"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,6]]},"references-count":12,"journal-issue":{"issue":"6","published-online":{"date-parts":[[1991,6,1]]},"published-print":{"date-parts":[[1991,6]]}},"alternative-id":["10.1136\/gut.32.6.670"],"URL":"https:\/\/doi.org\/10.1136\/gut.32.6.670","relation":{},"ISSN":["0017-5749","1468-3288"],"issn-type":[{"type":"print","value":"0017-5749"},{"type":"electronic","value":"1468-3288"}],"subject":[],"published":{"date-parts":[[1991,6]]}}}