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Sensory discrimination training in the treatment of a case of chronic constipation
BEHAVIORTHERAPY 18, 273-278, 1987
CASE STUDY Sensory Discrimination Training in the Treatment of a Case of Chronic Constipation JAMES A. MCCUBBIN RICHARD S. SURWlT
CHARLES M. MANSBACH Duke University Medical Center A 31-year-old woman with a history of life-long constipation and laxative dependence was treated with discrimination training for rectal sensation. She had complained of absence of the urge to defecate, bloating with abdominal discomfort, and need for laxatives to relieve symptoms. Manometric examination with an anorectal balloon assembly revealed a normal threshold for sphincteric reflexes, but an abnormally elevated threshold for detection of rectal distention. Behavioral treatment consisted of a manometrically based sensory discrimination procedure designed to reduce the sensory threshold for rectal distention. Multiple training sessions with this procedure allowed recognition of progressively smaller rectal distention volumes. Accompanying these changes in rectal sensory threshold were concomitant increases in the frequency of bowel movements, decreases in the weekly use of laxatives, and decreases in subjective discomfort. Therapeutic effects were maintained at follow-up examination one year later. The results of this case study suggest that behavioral training to increase rectal sensation may be useful in treating constipation in patients who have abnormal rectal sensory thresholds.
The role of behavioral methods in treatment of gastroenterologicai disorders has only recently been appreciated. Behaviorally based therapies have proven efficacious in treatment of several conditions, including fecal incontinence, irritable bowel syndrome, peptic ulcer disease and reflux esophagitis (Whitehead and Schuster, 1985; Marzuk, 1985). However, there are few widely accepted effective medical or behavioral treatments for chronic constipation. Most patients utilize various laxative preparations or dietary therapy in an attempt to induce regular bowel movements. If these remedies fail, patients seek professional treatment, which usually includes morning enemas, habit training, large The authors express grateful appreciation to Ms. Carolyn Baker for technical assistance. Requests for reprints should be sent to Dr. James A. McCubbin, Department of Psychiatry, Box 3926, Duke University Medical Center, Durham, NC 27710. 273 0005-7894/87/0273-027851.00/0 Copyright 1987 by Association for Advancement of Behavior Therapy All rights of reproduction in any form reserved.
274
MCCUBBIN, SURWIT, AND MANSBACH
doses of bulk laxatives, and in extreme cases, partial colectomy (De Vroede, 1983). Recent manometric studies have revealed an anorectal sensorimotor dysfunction in some patients with chronic constipation (Behar and Biancani, 1984; Read, Timms, Barfield, Donnelly and Bannister, 1986) and in diabetic patients with fecal incontinence (Wald and Tunuguntla, 1984). Many patients complained of an inability to detect rectal distention, and manometric evaluation confirmed increased volumetric thresholds for rectal sensation and for induction of the desire to defecate. These sensory deficits can occur in the absence of sphincter dysfunction, so behavioral methods could reinstate adequate sensation if the anatomical substrate is preserved. Therefore, it is possible that impaired anorectal sensory function contributes to irregularity o f bowel movements and, if so, improvement o f sensory discriminative capacity could result in significant clinical improvement. We now describe use o f sensory discrimination training to treat a case of chronic constipation in a young woman with anorectal sensory dysfunction.
METHODS Case Study The patient was a 31-year-old white female recreation therapist who complained of lifeqong constipation. She had hard scybalous stools for as long as she could remember, and for the past 15 years bulk laxatives and contact stimulatory agents had been required to produce a bowel movement. No pain had been associated with her symptoms. However, two months prior to seeking consultation, the patient noted the onset of crampy pain occurring at the level of the umbilicus which radiated bilaterally toward the back. This was associated with nausea and heartburn with occasional abdominal swelling and increased bowel sounds. These symptoms would worsen until a Fleet's enema or a suppository was utilized. The passage of stool would ease symptoms, but discomfort would recur after about two days without stool passage. There was no significant history of diarrhea. Intermittent rectal bleeding was ascribed to hemorrhoids. The patient was on no medications other than herein described. The patient's mother has constipation and Crohn's colitis. Physical and neurological examinations were within normal limits except for an external hemorrhoid. There was no positive history of psychological problems. Proctoscopy was normal with firm stool visualized within the rectal vault. Hemoglobin (12 g/dl), hematocrit (35.4o/o), white blood count, and differential were all within normal limits as were platelet counts, serum glucose, blood urea nitrogen, and serum electrolytes. A thyroid panel showed normal T3 uptake, thyroxin level, and free thyroxin index. A medical workup which included a barium x-ray was negative for Crohn's disease.
Materials A rectal balloon assembly (Arndorfer Medical Specialties, Greendale, WI) was used for manometric evaluation. The probe has 2 ports which are con-
DISCRIMINATION TRAINING IN CONSTIPATION
275
tinuously perfused with water at 0.5 ml/min and has a balloon at its proximal tip. Catheters were attached to Hewlett-Packard Model 1290A pressure transducers (Hewlett-Packard, Palo Alto, CA.). A low compliance hydraulic perfusion system (Arndorfer Medical Specialties) provided constant water perfusion. Pressures were recorded on a 4-channel polygraph (Hewlett-Packard Model 1064A). This allowed continuous monitoring o f the internal and external sphincter activity during volume challenges to the rectosigmoid vault. Using this procedure, the patient demonstrated normal thresholds for sphincteric reflexes (15-20 ml volume displacement), but an abnormally elevated threshold for rectal sensation (130-200 ml volume displacement). These values from our laboratory are consistent with previously published norms (Wald and Tunuguntla, 1984) and indicate normal sphincter function and the absence of Hirschsprung's Disease.
Procedures Intact sphincteric reflexes in association with abnormally elevated sensory threshold corroborated the patient's self-report o f lack o f perceived need for defecation. It was therefore hypothesized that the patient's complaints of constipation were related to the observed sensory deficits. A behavioral training program was devised to teach the patient to improve her ability to detect rectal distention. A discrimination training paradigm using successive approximations with immediate feedback and positive reinforcement was employed. Feedback consisted of immediately informing the patient verbally whether or not a stimulus had occurred. Positive reinforcement consisted o f verbal rewards for correct responses with encouragement for continued success. Variations o f this procedure have been described elsewhere (Wald and Tunuguntla, 1984). During each training trial, the rectal balloon was rapidly (0.5 seconds) inflated with a given volume of air and maintained for 5 seconds; then the air bolus was removed. The patient was unaware of the moment o f inflation. The initial manometric evaluation determined that the original sensory threshold was between 130 and 200 ml volume distention. The beginning volume for discrimination training was set at 150 ml since this volume was correctly identified in about 50°7o of evaluation trails. She was given 5 seconds to acknowledge awareness of the stimulus. This procedure was repeated using the same volume of air until the patient was able to identify the presence of the stimulus on seven of ten occasions. Following the attainment o f the 7007o criterion, the volume of air boli used during the next series of trials was decreased by 10 ml. Training sessions lasted 30 minutes and were held 1-2 times per week. A total of 20 training sessions were held over 3 months. The patient was also asked to identify a 15-minute period during the day when she could concentrate on rectal sensations and attempt to have a bowel movement. She was to engage in this procedure regardless o f whether or not she felt the urge to defecate. The patient was given a diary to be maintained daily. Each daily record included information regarding diet, the number o f bowel movements, and the
276
MCCUBBIN, SURWIT, AND MANSBACH
frequency of laxative use. The current diary entries were returned at each training session. All diary data were confirmed by self-report and spot checks for accuracy. During training, the patient was instructed to use laxatives only if absolutely necessary to prevent discomfort. All manometric evaluations and training procedures were performed with the bowels emptied via enema about 1 hour prior to testing. Data from individual sessions were averaged over weeks and months for evaluation of training-induced changes in sensory threshold. Diary data were transformed into weekly values and averaged across months.
RESULTS Initial manometric evaluation showed adequate sphincteric strength and endurance during voluntary squeeze maneuvers. Rectal distention revealed normal threshold for sphincteric reflexes at 15-20 ml volume displacement. This threshold remained at normal levels throughout the discrimination training and was not affected by training. Rectal sensory thresholds, on the other hand, were abnormally elevated to 130-200 ml volume displacement versus a 20 ml normal level. Over the course of training, the patient gradually improved her ability to recognize rectal sensation as indicated by a progressive reduction in the minimum detected volume of air boli distending the rectal vault. Figure 1 shows monthly averages of sensory threshold, bowel movement frequency, and total laxative intake during the three-month training period. This indicates concomitant reductions in sensory threshold and total laxative intake with moderate increases in the frequency of bowel movements. Three months of training produced an 85°7o reduction in minimum detected volume from an initial pretreatment level of 130 ml to less than 20 ml by the end of training. The values in Fig. 1 represent monthly averages and, therefore, do not reflect maximum or minimum data from individual trials. The patient's average total laxative intake (sum of bulk laxatives, enemas, suppositories) decreased from pretreatment frequencies of 2-3 per week to less than 1 every 2 weeks at the end of training. Bowel movement frequency increased moderately despite the decreased laxative intake. It is notable that the patient acquired the urge to defecate about halfway through the three-month protocol. This urge would occur in the morning as well as at various times throughout the day. Follow-up manometric examination at six months posttraining showed retention of rectal sensory integrity. Thresholds for sphincteric reflexes and for rectal sensation were consistently between 15-20 ml distending volume. The patient reported regular bowel movements and absence of need for laxatives. These clinical improvements were maintained at one year follow-up, indicating the long-term efficacy of training.
DISCUSSION Several investigators have noted a sensory deficit in young women with severe constipation. Read, Timms, Barfield, Donnelly, and Bannister (1986) found that some young women with severe constipation require higher rectal volumes
DISCRIMINATION TRAINING IN CONSTIPATION
oo
50
0
m
277
N
lO
0
1
2 Month
~
3
Fro. 1. Monthly averages of anorectal sensory threshold (A), total monthly bowel movement frequency (B), and total monthly laxative intake (C) during anorectal sensory discrimination training in a patient with chronic constipation.
to induce the desire to defecate, while Behar and Biancani (1984) observed the diminished ability to detect rectal volume distention in similar groups of patients. Our patient demonstrated normal sphincteric reflexes but an abnormally elevated threshold for sensory awareness of rectosigmoid distention. Normal rectal compliance and normal threshold for sphincteric reflexes confirmed the absence of Hirschsprung's Disease in this patient. Systematic behavioral training gradually normalized the patient's rectal sensory threshold abnormality. Changes in this sensory threshold were accompanied by increased awareness of the urge to defecate at home, a gradual increase in the frequency of bowel movements, and a simultaneous reduction in laxative use. The role of abnormal sensory thresholds in the etiology of constipation remains to be specified. Chronic constipation itself can produce sensory abnormalities as a result of altered rectal compliance and tonic adaptation of stretch receptors (Whitehead and Schuster, 1985). However, the normal sphincteric reflex threshold in our patient makes it unlikely that receptor adaptation was the major mechanism of sensory dysfunction and constipation. It is possible that patients learn to habitually ignore rectal sensations. Ignoring rectal sensation is reinforced in some employment settings, where work stoppage is difficult. The present case was a recreation therapist working with retarded children, and unscheduled breaks were often inconvenient. The role of habit training in production of the clinical improvement is an important issue, and some habit training procedures are an integral aspect of the present proce-
278
MCCUBBI/,I, SURW'IT, AND MANSBACH
dure. As outlined in the methods section, the patient was asked to identify a quiet time each day to concentrate on rectal sensations. The purpose of this was to allow the patient to apply learned sensory integrity to bowel-induced sensations. Ultimately, these new skills should produce the desired target behavior of bowel regularity. Standard habit training alone is efficacious in some cases of constipation, but this procedure had been used by our patient prior to the present study with no success. Furthermore, functional recovery was characterized by increased urges to defecate at various times throughout the day and not just during the instructed time. Therefore, the clinical improvements cannot be attributed to simple habit training alone. The results indicate that improving rectal sensory threshold facilitated the urge to defecate and increased bowel movement frequency from about 3.2 to 4 per week (Figure 1) in this patient. Although this change would not be considered clinically significant under normal circumstances, the improvement occurred simultaneously with decreased laxative usage. Therefore, the most significant clinical improvement relates to the ability of the patient to maintaln adequate bowel movement frequency while decreasing laxative consumption. The patient attributed her improvement to increased awareness of rectal sensations which prompted her to attempt to defecate regularly without the aid of laxatives. The long-term efficacy of this procedure is suggested by the results of six-month and one-year follow-up. Additional research is necessary first, to determine the incidence of anorectal sensory dysfunction in patients with constipation, and second, to establish the generality of the therapeutic effect in these patients. Nevertheless, the results of this case study suggest that behavioral training to increase rectal sensation may be useful in treatment of constipation in patients who have abnormal anorectal sensory thresholds.
REFERENCES Behar, J. and Biancani, P. (1984). Rectal function in patients with idiopathic chronic constipation. In C. Ramon (Ed.) Gastrointestinal motility (pp. 459-466). Lancaster, England: MTP Press. De Vroede, G. (1983). Constipation: Mechanisms and management. In M. H. Sleisinger and J. S. Fottran (Eds.) Gastrointestinal disease pathophysiology, diagnoses, and management (3rd edition, pp. 288-307). Philadelphia: W. B. Saunders. Marzuk, P. M. (1985). Biofeedback for gastrointestinal disorders: A review of the literature Annals of Internal Medicine, 103, 240-244. Read, N. W., Timms, J. M., Barfield, L. J., Donnelly, T. C. and Bannister, J. J. (1986). Impairment of defecation in young women with severe constipation. Gastroenterology, 90, 53-60. Wald, A. and Tunuguntla, A. K. (1984). Anorectal sensorimotor dysfunction in fecal incontinence and diabetes mellitus. New England Journal of Medicine, 310, 1282-1287. Whitehead, W. E. and Schuster, M. M. (1985). Gastrointestinaldisorders" Behavioral andphysiological basis for treatment. Orlando: Academic Press, Inc. I~CElVED: February 11, 1987 FINAL ACCEPTANCE: April 8, 1987
CASE STUDY Sensory Discrimination Training in the Treatment of a Case of Chronic Constipation JAMES A. MCCUBBIN RICHARD S. SURWlT
CHARLES M. MANSBACH Duke University Medical Center A 31-year-old woman with a history of life-long constipation and laxative dependence was treated with discrimination training for rectal sensation. She had complained of absence of the urge to defecate, bloating with abdominal discomfort, and need for laxatives to relieve symptoms. Manometric examination with an anorectal balloon assembly revealed a normal threshold for sphincteric reflexes, but an abnormally elevated threshold for detection of rectal distention. Behavioral treatment consisted of a manometrically based sensory discrimination procedure designed to reduce the sensory threshold for rectal distention. Multiple training sessions with this procedure allowed recognition of progressively smaller rectal distention volumes. Accompanying these changes in rectal sensory threshold were concomitant increases in the frequency of bowel movements, decreases in the weekly use of laxatives, and decreases in subjective discomfort. Therapeutic effects were maintained at follow-up examination one year later. The results of this case study suggest that behavioral training to increase rectal sensation may be useful in treating constipation in patients who have abnormal rectal sensory thresholds.
The role of behavioral methods in treatment of gastroenterologicai disorders has only recently been appreciated. Behaviorally based therapies have proven efficacious in treatment of several conditions, including fecal incontinence, irritable bowel syndrome, peptic ulcer disease and reflux esophagitis (Whitehead and Schuster, 1985; Marzuk, 1985). However, there are few widely accepted effective medical or behavioral treatments for chronic constipation. Most patients utilize various laxative preparations or dietary therapy in an attempt to induce regular bowel movements. If these remedies fail, patients seek professional treatment, which usually includes morning enemas, habit training, large The authors express grateful appreciation to Ms. Carolyn Baker for technical assistance. Requests for reprints should be sent to Dr. James A. McCubbin, Department of Psychiatry, Box 3926, Duke University Medical Center, Durham, NC 27710. 273 0005-7894/87/0273-027851.00/0 Copyright 1987 by Association for Advancement of Behavior Therapy All rights of reproduction in any form reserved.
274
MCCUBBIN, SURWIT, AND MANSBACH
doses of bulk laxatives, and in extreme cases, partial colectomy (De Vroede, 1983). Recent manometric studies have revealed an anorectal sensorimotor dysfunction in some patients with chronic constipation (Behar and Biancani, 1984; Read, Timms, Barfield, Donnelly and Bannister, 1986) and in diabetic patients with fecal incontinence (Wald and Tunuguntla, 1984). Many patients complained of an inability to detect rectal distention, and manometric evaluation confirmed increased volumetric thresholds for rectal sensation and for induction of the desire to defecate. These sensory deficits can occur in the absence of sphincter dysfunction, so behavioral methods could reinstate adequate sensation if the anatomical substrate is preserved. Therefore, it is possible that impaired anorectal sensory function contributes to irregularity o f bowel movements and, if so, improvement o f sensory discriminative capacity could result in significant clinical improvement. We now describe use o f sensory discrimination training to treat a case of chronic constipation in a young woman with anorectal sensory dysfunction.
METHODS Case Study The patient was a 31-year-old white female recreation therapist who complained of lifeqong constipation. She had hard scybalous stools for as long as she could remember, and for the past 15 years bulk laxatives and contact stimulatory agents had been required to produce a bowel movement. No pain had been associated with her symptoms. However, two months prior to seeking consultation, the patient noted the onset of crampy pain occurring at the level of the umbilicus which radiated bilaterally toward the back. This was associated with nausea and heartburn with occasional abdominal swelling and increased bowel sounds. These symptoms would worsen until a Fleet's enema or a suppository was utilized. The passage of stool would ease symptoms, but discomfort would recur after about two days without stool passage. There was no significant history of diarrhea. Intermittent rectal bleeding was ascribed to hemorrhoids. The patient was on no medications other than herein described. The patient's mother has constipation and Crohn's colitis. Physical and neurological examinations were within normal limits except for an external hemorrhoid. There was no positive history of psychological problems. Proctoscopy was normal with firm stool visualized within the rectal vault. Hemoglobin (12 g/dl), hematocrit (35.4o/o), white blood count, and differential were all within normal limits as were platelet counts, serum glucose, blood urea nitrogen, and serum electrolytes. A thyroid panel showed normal T3 uptake, thyroxin level, and free thyroxin index. A medical workup which included a barium x-ray was negative for Crohn's disease.
Materials A rectal balloon assembly (Arndorfer Medical Specialties, Greendale, WI) was used for manometric evaluation. The probe has 2 ports which are con-
DISCRIMINATION TRAINING IN CONSTIPATION
275
tinuously perfused with water at 0.5 ml/min and has a balloon at its proximal tip. Catheters were attached to Hewlett-Packard Model 1290A pressure transducers (Hewlett-Packard, Palo Alto, CA.). A low compliance hydraulic perfusion system (Arndorfer Medical Specialties) provided constant water perfusion. Pressures were recorded on a 4-channel polygraph (Hewlett-Packard Model 1064A). This allowed continuous monitoring o f the internal and external sphincter activity during volume challenges to the rectosigmoid vault. Using this procedure, the patient demonstrated normal thresholds for sphincteric reflexes (15-20 ml volume displacement), but an abnormally elevated threshold for rectal sensation (130-200 ml volume displacement). These values from our laboratory are consistent with previously published norms (Wald and Tunuguntla, 1984) and indicate normal sphincter function and the absence of Hirschsprung's Disease.
Procedures Intact sphincteric reflexes in association with abnormally elevated sensory threshold corroborated the patient's self-report o f lack o f perceived need for defecation. It was therefore hypothesized that the patient's complaints of constipation were related to the observed sensory deficits. A behavioral training program was devised to teach the patient to improve her ability to detect rectal distention. A discrimination training paradigm using successive approximations with immediate feedback and positive reinforcement was employed. Feedback consisted of immediately informing the patient verbally whether or not a stimulus had occurred. Positive reinforcement consisted o f verbal rewards for correct responses with encouragement for continued success. Variations o f this procedure have been described elsewhere (Wald and Tunuguntla, 1984). During each training trial, the rectal balloon was rapidly (0.5 seconds) inflated with a given volume of air and maintained for 5 seconds; then the air bolus was removed. The patient was unaware of the moment o f inflation. The initial manometric evaluation determined that the original sensory threshold was between 130 and 200 ml volume distention. The beginning volume for discrimination training was set at 150 ml since this volume was correctly identified in about 50°7o of evaluation trails. She was given 5 seconds to acknowledge awareness of the stimulus. This procedure was repeated using the same volume of air until the patient was able to identify the presence of the stimulus on seven of ten occasions. Following the attainment o f the 7007o criterion, the volume of air boli used during the next series of trials was decreased by 10 ml. Training sessions lasted 30 minutes and were held 1-2 times per week. A total of 20 training sessions were held over 3 months. The patient was also asked to identify a 15-minute period during the day when she could concentrate on rectal sensations and attempt to have a bowel movement. She was to engage in this procedure regardless o f whether or not she felt the urge to defecate. The patient was given a diary to be maintained daily. Each daily record included information regarding diet, the number o f bowel movements, and the
276
MCCUBBIN, SURWIT, AND MANSBACH
frequency of laxative use. The current diary entries were returned at each training session. All diary data were confirmed by self-report and spot checks for accuracy. During training, the patient was instructed to use laxatives only if absolutely necessary to prevent discomfort. All manometric evaluations and training procedures were performed with the bowels emptied via enema about 1 hour prior to testing. Data from individual sessions were averaged over weeks and months for evaluation of training-induced changes in sensory threshold. Diary data were transformed into weekly values and averaged across months.
RESULTS Initial manometric evaluation showed adequate sphincteric strength and endurance during voluntary squeeze maneuvers. Rectal distention revealed normal threshold for sphincteric reflexes at 15-20 ml volume displacement. This threshold remained at normal levels throughout the discrimination training and was not affected by training. Rectal sensory thresholds, on the other hand, were abnormally elevated to 130-200 ml volume displacement versus a 20 ml normal level. Over the course of training, the patient gradually improved her ability to recognize rectal sensation as indicated by a progressive reduction in the minimum detected volume of air boli distending the rectal vault. Figure 1 shows monthly averages of sensory threshold, bowel movement frequency, and total laxative intake during the three-month training period. This indicates concomitant reductions in sensory threshold and total laxative intake with moderate increases in the frequency of bowel movements. Three months of training produced an 85°7o reduction in minimum detected volume from an initial pretreatment level of 130 ml to less than 20 ml by the end of training. The values in Fig. 1 represent monthly averages and, therefore, do not reflect maximum or minimum data from individual trials. The patient's average total laxative intake (sum of bulk laxatives, enemas, suppositories) decreased from pretreatment frequencies of 2-3 per week to less than 1 every 2 weeks at the end of training. Bowel movement frequency increased moderately despite the decreased laxative intake. It is notable that the patient acquired the urge to defecate about halfway through the three-month protocol. This urge would occur in the morning as well as at various times throughout the day. Follow-up manometric examination at six months posttraining showed retention of rectal sensory integrity. Thresholds for sphincteric reflexes and for rectal sensation were consistently between 15-20 ml distending volume. The patient reported regular bowel movements and absence of need for laxatives. These clinical improvements were maintained at one year follow-up, indicating the long-term efficacy of training.
DISCUSSION Several investigators have noted a sensory deficit in young women with severe constipation. Read, Timms, Barfield, Donnelly, and Bannister (1986) found that some young women with severe constipation require higher rectal volumes
DISCRIMINATION TRAINING IN CONSTIPATION
oo
50
0
m
277
N
lO
0
1
2 Month
~
3
Fro. 1. Monthly averages of anorectal sensory threshold (A), total monthly bowel movement frequency (B), and total monthly laxative intake (C) during anorectal sensory discrimination training in a patient with chronic constipation.
to induce the desire to defecate, while Behar and Biancani (1984) observed the diminished ability to detect rectal volume distention in similar groups of patients. Our patient demonstrated normal sphincteric reflexes but an abnormally elevated threshold for sensory awareness of rectosigmoid distention. Normal rectal compliance and normal threshold for sphincteric reflexes confirmed the absence of Hirschsprung's Disease in this patient. Systematic behavioral training gradually normalized the patient's rectal sensory threshold abnormality. Changes in this sensory threshold were accompanied by increased awareness of the urge to defecate at home, a gradual increase in the frequency of bowel movements, and a simultaneous reduction in laxative use. The role of abnormal sensory thresholds in the etiology of constipation remains to be specified. Chronic constipation itself can produce sensory abnormalities as a result of altered rectal compliance and tonic adaptation of stretch receptors (Whitehead and Schuster, 1985). However, the normal sphincteric reflex threshold in our patient makes it unlikely that receptor adaptation was the major mechanism of sensory dysfunction and constipation. It is possible that patients learn to habitually ignore rectal sensations. Ignoring rectal sensation is reinforced in some employment settings, where work stoppage is difficult. The present case was a recreation therapist working with retarded children, and unscheduled breaks were often inconvenient. The role of habit training in production of the clinical improvement is an important issue, and some habit training procedures are an integral aspect of the present proce-
278
MCCUBBI/,I, SURW'IT, AND MANSBACH
dure. As outlined in the methods section, the patient was asked to identify a quiet time each day to concentrate on rectal sensations. The purpose of this was to allow the patient to apply learned sensory integrity to bowel-induced sensations. Ultimately, these new skills should produce the desired target behavior of bowel regularity. Standard habit training alone is efficacious in some cases of constipation, but this procedure had been used by our patient prior to the present study with no success. Furthermore, functional recovery was characterized by increased urges to defecate at various times throughout the day and not just during the instructed time. Therefore, the clinical improvements cannot be attributed to simple habit training alone. The results indicate that improving rectal sensory threshold facilitated the urge to defecate and increased bowel movement frequency from about 3.2 to 4 per week (Figure 1) in this patient. Although this change would not be considered clinically significant under normal circumstances, the improvement occurred simultaneously with decreased laxative usage. Therefore, the most significant clinical improvement relates to the ability of the patient to maintaln adequate bowel movement frequency while decreasing laxative consumption. The patient attributed her improvement to increased awareness of rectal sensations which prompted her to attempt to defecate regularly without the aid of laxatives. The long-term efficacy of this procedure is suggested by the results of six-month and one-year follow-up. Additional research is necessary first, to determine the incidence of anorectal sensory dysfunction in patients with constipation, and second, to establish the generality of the therapeutic effect in these patients. Nevertheless, the results of this case study suggest that behavioral training to increase rectal sensation may be useful in treatment of constipation in patients who have abnormal anorectal sensory thresholds.
REFERENCES Behar, J. and Biancani, P. (1984). Rectal function in patients with idiopathic chronic constipation. In C. Ramon (Ed.) Gastrointestinal motility (pp. 459-466). Lancaster, England: MTP Press. De Vroede, G. (1983). Constipation: Mechanisms and management. In M. H. Sleisinger and J. S. Fottran (Eds.) Gastrointestinal disease pathophysiology, diagnoses, and management (3rd edition, pp. 288-307). Philadelphia: W. B. Saunders. Marzuk, P. M. (1985). Biofeedback for gastrointestinal disorders: A review of the literature Annals of Internal Medicine, 103, 240-244. Read, N. W., Timms, J. M., Barfield, L. J., Donnelly, T. C. and Bannister, J. J. (1986). Impairment of defecation in young women with severe constipation. Gastroenterology, 90, 53-60. Wald, A. and Tunuguntla, A. K. (1984). Anorectal sensorimotor dysfunction in fecal incontinence and diabetes mellitus. New England Journal of Medicine, 310, 1282-1287. Whitehead, W. E. and Schuster, M. M. (1985). Gastrointestinaldisorders" Behavioral andphysiological basis for treatment. Orlando: Academic Press, Inc. I~CElVED: February 11, 1987 FINAL ACCEPTANCE: April 8, 1987