Psychogenic Abdominal Pain Peter L. G. Jenkins, M.R.C.Psych.
Abstract: A series of 25 patients referred for psychiatric consultation with nonspecific abdominal pain (NSAP) are compared with a prospectively admitted series who were not referred. The rqferred patients had a longer duration of pain and also had high levels of psychiatric illness. The referred patientshad more life events associated with the onset of their pain than controls. inquiry about previous psychiatric history, childhood abuse, and a symptom model would increase the detection of NSAP patients who require psychiatric evaluation. Outcome after recommended treatmentis also addressed.
Introduction In acute abdominal pain, surgical diagnoses were assigned in fewer than 50% of cases of a consecutive series of 1000 admissions to an American surgical service [l]. In a prospective study of psychologic morbidity in general surgical patients [2], 24% (n = 51) were for nonspecific abdominal pain (NSAP), defined as abdominal pain for which no surgical cause was determined. Because of the frequency of NSAP in both surgical admissions and in the general population, where symptoms have been found in as many as one third of people, most definitions of irritable bowel syndrome (IBS) require a duration of 3 months or more. IBS has been defined as “the persistence of abdominal pain for longer than 3 months in the absence of any demonstrable underlying organic disease” [3]. Such a definition, however, confines the patient population to those who have chronic pain and neglects the fact that somatic symptoms are also present in normal and neurotic individuals in response to stress. From the Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom. Address reprint requests to: Dr. Peter L. C. Jenkins, DeDartment of Psvcholotical Medicine, University of Wales ColPark, Cardiff CFi 4XN, United iege of Medic&e, &ath Kingdom. Gemd Hospital Psychiatry13,27-30, 1991 0 1991 Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010
The present study compares a group of patients with NSAP referred for psychiatric consultation with an unselected prospective sample of patients admitted with NSAP. In the present study diagnoses were assigned according to DSM-III criteria, which are operationalized, widely accepted, and have a good reliability 141. In a recent review of life events and IBS, Creed et al. [5] draw attention to the many methodological problems in investigations of the relationship of life events to IBS. The evaluation of the temporal relationships between life events, psychiatric illness, and NSAP is complex and the present study attempts to address this issue. Management of psychogenic abdominal pain (PAP) and IBS is of significant importance. The disorders are common. Patients with somatization disorder have more sick days per month, and they expend up to ninefold the health care costs of the 15-64 year age group [6]. Additionally, such patients are liable to polysurgery and run the risk of iatrogenic injury [7]. The present study attempts to assess the efficacy of recommended treatment in referred patients.
Methods Consultation
Group
Twenty-five patients, who were referred to the author for psychiatric consultation with abdominal pain for which no organic cause had been found, were examined. These patients formed part of a larger series of consultation requests that were prospectively collected over a 2-year period from general surgeons at the University of Wales College of Medicine. All patients were seen as part of the liaison service offered by the author and their evaluation in27
ISSN 0163~8343/91/53.50
P. L. G. Jenkins
eluded a full psychiatric interview which, in addition to including the standard history and mental status exam, specifically sought information regarding life events associated with the pain and also resulted in treatment recommendations to the patient. Diagnoses were assigned according to DSM-III criteria.
NSAP Comparison Group The comparison group consisted of a prospective series of 51 admissions for NSAP who were taken from a prospective series of general surgical admissions already reported [2]. As previously described, the comparison group was screened using the General Health Questionnaire and those scoring above 11 interviewed using the Composite International Diagnostic Interview.
Table 1. Assignment consultation Diagnosis Major depression Anxiety disorder No diagnosis Psychogenic pain Conversion Alcoholism Did not attend Total
of diagnoses in the and control groups
Consultation group Control group 7 1
2 6 5
3 9 6 0 0
1
0
3
0
25
18
(X’ 14.99, p = O.OOOl), suggesting that psychiatric morbidity is accurately identified by surgeons working with these patient groups.
Matched Controls
Validity of the Screening Questions
To analyze some aspects in greater detail, patients were matched as follows. The patient from the consultation group was matched with the same-sexed individual in the NSAP group closest to him or her in age. Twenty-one patients were matched. Four patients (Nos. 18,21,28, and 35) were not matched as they had no pairs in their age cohort. Three of these had declined psychiatric examination.
Adequate documentation to enable comparison regarding the presence of a psychiatric history, symptom model, and childhood abuse was present in only 15 of the matched patients. Three patients from the matched control group reported psychiatric treatment compared with 8 of the consultation group, a difference that was not significant (X’ 2.3, p = 0.13). When all the consultation referrals were compared with the 51 NSAP patients in the comparison group, however, this difference reached significance. Regarding symptom model, only one of the matched control patients had a symptom model for his pain, which was significantly fewer than the PAP patients, 9 of whom reported a symptom model (X’ 7.35, p < 0.01). Childhood abuse was detected in 4 of the control patients compared with 9 from the consultation group. This was not a significant difference (X” 2.17, p = 0.14). When the presence of two or more of the three items was compared in the two groups the difference was highly significant (p < O.OOOl), and the presence of two of three factors was a useful discriminant (sensitivity 1.0, specificity 0.47, positive predictive value 0.65). One possibility might be that surgeons tend to refer patients with either a symptom model, previous psychiatric history, or history of childhood abuse. To investigate this the validity of the screening questions was assessed within all the patients referred for consultation during the study period (see Table 2).
Results The consultation group comprised 22 women and 3 men of mean age 44 years with a range of 18-77 years. The control group included 34 female and 16 male subjects who did not significantly differ from the consultation group (X’ 1.32, p = 0.25). The control group’s mean age was 41 years, range 16-76 years (no significant difference). Duration ofPain. In the PAP group the duration of pain ranged from 6 months to 37 years with a mean of 8.47 years. Review of the medical records of the matched control patients showed that the duration of pain in these cases was significantly shorter, ranging from 1 day to 6 weeks, with a mean duration of 5.56 days.
Psychiatric Diagnoses The assignment of diagnoses in the consultation and control groups is tabulated in Table 1. There is a highly significant correlation between the presence of a psychiatric diagnosis and referral 28
Psychogenic
Table 2. Assessment questions”
of validity of screening
Consultation group
Other diagnoses
Positive
10
7 (5 major depression, 1 anxiety, 1 no diagnosis)
Negative
6
20
“Based on two out of three screenings. Sensitivity = 0.625, specificity = 0.74, positive predictive value = 0.59.
Life Events Associated with the Onset of NSAP In the clinical interview of the consultation group patients, particular attention was directed towards the presence of life events associated with the development of the abdominal pain with which patients presented. Only three individuals reported no associated life events. Twenty-two individuals reported one or more severe life events and these were similar to those found in patients with depressive disorder [8]. In 14 patients the events, psychiatric illness, and pain occurred simultaneously. In six patients, event preceded pain and psychiatric illness followed. In two patients event, then psychiatric illness, then pain was the pattern. In one case psychiatric illness was independent of pain, but both were preceded by an event. In one patient life events preceded both pain and psychiatric ill health but their relationship could not be determined. A follow-up questionnaire was sent to the matched control patients asking them to report whether any significant life events had occurred in the 6 months preceding admission. Seven of the 11 respondents reported no life events and four reported eight life events between them. Life events thus discriminated between the groups with a sensitivity of 0.88, specificity of 0.64, and positive predictive value of 0.85.
Follow-up Data Follow-up data were obtained in 12 of the patients referred for consultation and diagnosed as suffering from PAP. Eleven of these patients had had psychiatric treatments such as antidepressants or relaxation prescribed and one had not followed through. Eight patients were rated as improved and four patients, including the one who did not comply, were rated as having had no change.
Abdominal Pain
Discussion To assist surgeons in the identification of suitable patients for whom psychiatric evaluation is appropriate, the present study confirms that female sex, duration of pain, and three screening questions may together raise the index of suspicion. The site and type of pain described do not clearly differentiate between the groups. Illustrating the problems of duration, Woodhouse and Bockner’s study [9] included only patients aged 18 years or over with more than 2 years’ duration of abdominal pain and showed 40% (n = 8) to have psychiatric diagnosis, a finding supported by the present study. In the present study, evaluation of the consultation group disclosed high levels of psychiatric morbidity, confirming the reports of previous studies [lo]. The most common diagnoses were of anxiety disorders, depressive disorders, and somatization disorders such as conversion or somatoform pain disorder. Previous studies have defined such disorders poorly. One example of a study with this problem was Gomez and Dally’s [ll], which assigned diagnosis to all patients by clinical judgment, which is of poor interrater reliability in general. That study showed higher scores on the Neuroticism subscale of the Eysenck personality inventory, elevated scores on the Hamilton rating scales for depression and anxiety and no significant difference in life events. In a later study MacDonald and Bouchier [12] assessed 67 patients with abdominal pain using structured interviews and blind evaluations by psychiatrist and physician. This study demonstrated a clear excess of psychiatric morbidity in the nonorganic group (53%) compared with the organic group (20%). It also allowed patients with IBS to be classified as not mentally ill in 18% of cases. The present study evaluated the ability of three factors identified by Eisendrath et al. [13] to discriminate between patients with PAP and other surgical patients, both referred and control patients. The utility of these questions was confirmed in the present study. To confirm the clinical importance of these factors in identifying those patients who have PAP from those whose NSAP reflects only an acute event, it would be necessary to conduct prospective studies of the NSAP group. Life events have been shown to play an important role in the precipitation of depressive illness in susceptible individuals, and the role of life events was also confirmed in the PAP group in the
29
P. L. G. Jenkins
present study. Compared with age- and sexmatched controls who were not referred, the PAP group had more reported life events in association with the onset of the abdominal pain, and the onset of psychiatric illness was simultaneous, suggesting that the abdominal pain may be a somatic predistress. Further sentation of psychologic studies would be required to evaluate whether NSAP shares other features of psychiatric disorders like depression, which shows an elevated prevalence among family members. Such studies may help differentiate whether the presence of a symptom model in these patients’ relatives reflects an underlying shared biologic diathesis or serves as a form of role modeling or identification. A wide variety of management approaches has been suggested. Drossman (141, in his study of 24 patients over 6 years, suggested a number of goals for management. In this group of 20 females and four males the average age was 34 and duration 6 years. At the time of the study’s termination, 22% had severe or moderate pain. Ten had used pregnancy fantasies to describe the pain. Drossman’s management recommendations stress conservative approaches. Other studies have suggested treatment of the associated psychiatric conditions and have shown an improved response to psychotherapy plus medication compared with medication alone [15]. As duration has been clearly shown to be associated with poor outcome and pediatric PAP has been shown to persist into adult life [18], behavioral strategies to de-emphasize illness behavior have also been advocated [ 151. The high prevalence of psychiatric morbidity such as depression in this group of patients and the relatively good outcome in the proportion of patients who had either psychologic or psychopharmacologic treatments in the present study suggest that intervention in a systematic fashion may enable the development of treatment protocols to assist these patients, who otherwise run the risk
30
of repeated surgery and who consume a disproportionate share of health resources.
References 1. Brewer RJ, Golden GT, Hitch DC, et al: An analysis of 1000 consecutive cases of abdominal pain in a university hospital emergency room. Am J Surg 131:219-223, 1976 2. Jenkins PL, Jamil N, Taylor B: Pre-operative psychological morbidity in general surgical patients. Presented at the Spring Quarterly Meeting of the Royal College of Psychiatrists, Leeds, 1989 3. Ford MJ: The irritable bowel syndrome invited review. J Psychosom Res 30(4):399-410, 1986 4. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 3rd ed. Washington, DC, APA, 1980 5. Creed F, Craig T, Farmer R: Functional abdominal pain, psychiatric illness and life events. Gut 29(2):235-242, 1988 6. Smith JGR, Monson RA, Ray DC: Patients with multiple unexplained symptoms. Arch Intern Med 146:69-72, 1986 7. De Vaul RA, Faillance LA: Persistent pain and illness insistence. A medical profile of proneness to surgery. Am J Surg 135:828-833, 1978 8. Brugha TS, Bebbington P, Tennat C, Hurry J: The list of threatening experiences: A subset of 12 life event categories with considerable contextual threat. Psycho1 Med 15:189-194, 1985 9. Woodhouse CRJ, Bockner S: Chronic abdominal pain: A surgical or psychiatric symptom? Br J Surg 66:348-349, 1979 10. Drossman DA: The patient with chronic undiagnosed abdominal pain. Hosp Pratt 2:22-29, 1986 11. Gomez J, Dally I’: Psychologically mediated abdominal pain in surgical and medical outpatient clinics. Br Med J 1:1451-1453, 1977 12. MacDonald AJ, Bouchier IAD: Non-organic gastrointestinal illness: A medical and psychiatric study. Br J Psychiatry 136:276-283, 1980 13. Eisendrath SJ, Way LW, Ostroff JW, Johnson CA: Identification of psychogenic abdominal pain. Psychosomatics 27(10):705-712, 1986 14. Drossman DA: Patients with psychogenic abdominal pain. 6 years’ observation. Am J Psychiatry 139:15491557, 1982 15. Creed F, Guthrie E: Psychological treatment of the irritable bowel syndrome: A review. Gut 30:1989
Abstract: A series of 25 patients referred for psychiatric consultation with nonspecific abdominal pain (NSAP) are compared with a prospectively admitted series who were not referred. The rqferred patients had a longer duration of pain and also had high levels of psychiatric illness. The referred patientshad more life events associated with the onset of their pain than controls. inquiry about previous psychiatric history, childhood abuse, and a symptom model would increase the detection of NSAP patients who require psychiatric evaluation. Outcome after recommended treatmentis also addressed.
Introduction In acute abdominal pain, surgical diagnoses were assigned in fewer than 50% of cases of a consecutive series of 1000 admissions to an American surgical service [l]. In a prospective study of psychologic morbidity in general surgical patients [2], 24% (n = 51) were for nonspecific abdominal pain (NSAP), defined as abdominal pain for which no surgical cause was determined. Because of the frequency of NSAP in both surgical admissions and in the general population, where symptoms have been found in as many as one third of people, most definitions of irritable bowel syndrome (IBS) require a duration of 3 months or more. IBS has been defined as “the persistence of abdominal pain for longer than 3 months in the absence of any demonstrable underlying organic disease” [3]. Such a definition, however, confines the patient population to those who have chronic pain and neglects the fact that somatic symptoms are also present in normal and neurotic individuals in response to stress. From the Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom. Address reprint requests to: Dr. Peter L. C. Jenkins, DeDartment of Psvcholotical Medicine, University of Wales ColPark, Cardiff CFi 4XN, United iege of Medic&e, &ath Kingdom. Gemd Hospital Psychiatry13,27-30, 1991 0 1991 Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010
The present study compares a group of patients with NSAP referred for psychiatric consultation with an unselected prospective sample of patients admitted with NSAP. In the present study diagnoses were assigned according to DSM-III criteria, which are operationalized, widely accepted, and have a good reliability 141. In a recent review of life events and IBS, Creed et al. [5] draw attention to the many methodological problems in investigations of the relationship of life events to IBS. The evaluation of the temporal relationships between life events, psychiatric illness, and NSAP is complex and the present study attempts to address this issue. Management of psychogenic abdominal pain (PAP) and IBS is of significant importance. The disorders are common. Patients with somatization disorder have more sick days per month, and they expend up to ninefold the health care costs of the 15-64 year age group [6]. Additionally, such patients are liable to polysurgery and run the risk of iatrogenic injury [7]. The present study attempts to assess the efficacy of recommended treatment in referred patients.
Methods Consultation
Group
Twenty-five patients, who were referred to the author for psychiatric consultation with abdominal pain for which no organic cause had been found, were examined. These patients formed part of a larger series of consultation requests that were prospectively collected over a 2-year period from general surgeons at the University of Wales College of Medicine. All patients were seen as part of the liaison service offered by the author and their evaluation in27
ISSN 0163~8343/91/53.50
P. L. G. Jenkins
eluded a full psychiatric interview which, in addition to including the standard history and mental status exam, specifically sought information regarding life events associated with the pain and also resulted in treatment recommendations to the patient. Diagnoses were assigned according to DSM-III criteria.
NSAP Comparison Group The comparison group consisted of a prospective series of 51 admissions for NSAP who were taken from a prospective series of general surgical admissions already reported [2]. As previously described, the comparison group was screened using the General Health Questionnaire and those scoring above 11 interviewed using the Composite International Diagnostic Interview.
Table 1. Assignment consultation Diagnosis Major depression Anxiety disorder No diagnosis Psychogenic pain Conversion Alcoholism Did not attend Total
of diagnoses in the and control groups
Consultation group Control group 7 1
2 6 5
3 9 6 0 0
1
0
3
0
25
18
(X’ 14.99, p = O.OOOl), suggesting that psychiatric morbidity is accurately identified by surgeons working with these patient groups.
Matched Controls
Validity of the Screening Questions
To analyze some aspects in greater detail, patients were matched as follows. The patient from the consultation group was matched with the same-sexed individual in the NSAP group closest to him or her in age. Twenty-one patients were matched. Four patients (Nos. 18,21,28, and 35) were not matched as they had no pairs in their age cohort. Three of these had declined psychiatric examination.
Adequate documentation to enable comparison regarding the presence of a psychiatric history, symptom model, and childhood abuse was present in only 15 of the matched patients. Three patients from the matched control group reported psychiatric treatment compared with 8 of the consultation group, a difference that was not significant (X’ 2.3, p = 0.13). When all the consultation referrals were compared with the 51 NSAP patients in the comparison group, however, this difference reached significance. Regarding symptom model, only one of the matched control patients had a symptom model for his pain, which was significantly fewer than the PAP patients, 9 of whom reported a symptom model (X’ 7.35, p < 0.01). Childhood abuse was detected in 4 of the control patients compared with 9 from the consultation group. This was not a significant difference (X” 2.17, p = 0.14). When the presence of two or more of the three items was compared in the two groups the difference was highly significant (p < O.OOOl), and the presence of two of three factors was a useful discriminant (sensitivity 1.0, specificity 0.47, positive predictive value 0.65). One possibility might be that surgeons tend to refer patients with either a symptom model, previous psychiatric history, or history of childhood abuse. To investigate this the validity of the screening questions was assessed within all the patients referred for consultation during the study period (see Table 2).
Results The consultation group comprised 22 women and 3 men of mean age 44 years with a range of 18-77 years. The control group included 34 female and 16 male subjects who did not significantly differ from the consultation group (X’ 1.32, p = 0.25). The control group’s mean age was 41 years, range 16-76 years (no significant difference). Duration ofPain. In the PAP group the duration of pain ranged from 6 months to 37 years with a mean of 8.47 years. Review of the medical records of the matched control patients showed that the duration of pain in these cases was significantly shorter, ranging from 1 day to 6 weeks, with a mean duration of 5.56 days.
Psychiatric Diagnoses The assignment of diagnoses in the consultation and control groups is tabulated in Table 1. There is a highly significant correlation between the presence of a psychiatric diagnosis and referral 28
Psychogenic
Table 2. Assessment questions”
of validity of screening
Consultation group
Other diagnoses
Positive
10
7 (5 major depression, 1 anxiety, 1 no diagnosis)
Negative
6
20
“Based on two out of three screenings. Sensitivity = 0.625, specificity = 0.74, positive predictive value = 0.59.
Life Events Associated with the Onset of NSAP In the clinical interview of the consultation group patients, particular attention was directed towards the presence of life events associated with the development of the abdominal pain with which patients presented. Only three individuals reported no associated life events. Twenty-two individuals reported one or more severe life events and these were similar to those found in patients with depressive disorder [8]. In 14 patients the events, psychiatric illness, and pain occurred simultaneously. In six patients, event preceded pain and psychiatric illness followed. In two patients event, then psychiatric illness, then pain was the pattern. In one case psychiatric illness was independent of pain, but both were preceded by an event. In one patient life events preceded both pain and psychiatric ill health but their relationship could not be determined. A follow-up questionnaire was sent to the matched control patients asking them to report whether any significant life events had occurred in the 6 months preceding admission. Seven of the 11 respondents reported no life events and four reported eight life events between them. Life events thus discriminated between the groups with a sensitivity of 0.88, specificity of 0.64, and positive predictive value of 0.85.
Follow-up Data Follow-up data were obtained in 12 of the patients referred for consultation and diagnosed as suffering from PAP. Eleven of these patients had had psychiatric treatments such as antidepressants or relaxation prescribed and one had not followed through. Eight patients were rated as improved and four patients, including the one who did not comply, were rated as having had no change.
Abdominal Pain
Discussion To assist surgeons in the identification of suitable patients for whom psychiatric evaluation is appropriate, the present study confirms that female sex, duration of pain, and three screening questions may together raise the index of suspicion. The site and type of pain described do not clearly differentiate between the groups. Illustrating the problems of duration, Woodhouse and Bockner’s study [9] included only patients aged 18 years or over with more than 2 years’ duration of abdominal pain and showed 40% (n = 8) to have psychiatric diagnosis, a finding supported by the present study. In the present study, evaluation of the consultation group disclosed high levels of psychiatric morbidity, confirming the reports of previous studies [lo]. The most common diagnoses were of anxiety disorders, depressive disorders, and somatization disorders such as conversion or somatoform pain disorder. Previous studies have defined such disorders poorly. One example of a study with this problem was Gomez and Dally’s [ll], which assigned diagnosis to all patients by clinical judgment, which is of poor interrater reliability in general. That study showed higher scores on the Neuroticism subscale of the Eysenck personality inventory, elevated scores on the Hamilton rating scales for depression and anxiety and no significant difference in life events. In a later study MacDonald and Bouchier [12] assessed 67 patients with abdominal pain using structured interviews and blind evaluations by psychiatrist and physician. This study demonstrated a clear excess of psychiatric morbidity in the nonorganic group (53%) compared with the organic group (20%). It also allowed patients with IBS to be classified as not mentally ill in 18% of cases. The present study evaluated the ability of three factors identified by Eisendrath et al. [13] to discriminate between patients with PAP and other surgical patients, both referred and control patients. The utility of these questions was confirmed in the present study. To confirm the clinical importance of these factors in identifying those patients who have PAP from those whose NSAP reflects only an acute event, it would be necessary to conduct prospective studies of the NSAP group. Life events have been shown to play an important role in the precipitation of depressive illness in susceptible individuals, and the role of life events was also confirmed in the PAP group in the
29
P. L. G. Jenkins
present study. Compared with age- and sexmatched controls who were not referred, the PAP group had more reported life events in association with the onset of the abdominal pain, and the onset of psychiatric illness was simultaneous, suggesting that the abdominal pain may be a somatic predistress. Further sentation of psychologic studies would be required to evaluate whether NSAP shares other features of psychiatric disorders like depression, which shows an elevated prevalence among family members. Such studies may help differentiate whether the presence of a symptom model in these patients’ relatives reflects an underlying shared biologic diathesis or serves as a form of role modeling or identification. A wide variety of management approaches has been suggested. Drossman (141, in his study of 24 patients over 6 years, suggested a number of goals for management. In this group of 20 females and four males the average age was 34 and duration 6 years. At the time of the study’s termination, 22% had severe or moderate pain. Ten had used pregnancy fantasies to describe the pain. Drossman’s management recommendations stress conservative approaches. Other studies have suggested treatment of the associated psychiatric conditions and have shown an improved response to psychotherapy plus medication compared with medication alone [15]. As duration has been clearly shown to be associated with poor outcome and pediatric PAP has been shown to persist into adult life [18], behavioral strategies to de-emphasize illness behavior have also been advocated [ 151. The high prevalence of psychiatric morbidity such as depression in this group of patients and the relatively good outcome in the proportion of patients who had either psychologic or psychopharmacologic treatments in the present study suggest that intervention in a systematic fashion may enable the development of treatment protocols to assist these patients, who otherwise run the risk
30
of repeated surgery and who consume a disproportionate share of health resources.
References 1. Brewer RJ, Golden GT, Hitch DC, et al: An analysis of 1000 consecutive cases of abdominal pain in a university hospital emergency room. Am J Surg 131:219-223, 1976 2. Jenkins PL, Jamil N, Taylor B: Pre-operative psychological morbidity in general surgical patients. Presented at the Spring Quarterly Meeting of the Royal College of Psychiatrists, Leeds, 1989 3. Ford MJ: The irritable bowel syndrome invited review. J Psychosom Res 30(4):399-410, 1986 4. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 3rd ed. Washington, DC, APA, 1980 5. Creed F, Craig T, Farmer R: Functional abdominal pain, psychiatric illness and life events. Gut 29(2):235-242, 1988 6. Smith JGR, Monson RA, Ray DC: Patients with multiple unexplained symptoms. Arch Intern Med 146:69-72, 1986 7. De Vaul RA, Faillance LA: Persistent pain and illness insistence. A medical profile of proneness to surgery. Am J Surg 135:828-833, 1978 8. Brugha TS, Bebbington P, Tennat C, Hurry J: The list of threatening experiences: A subset of 12 life event categories with considerable contextual threat. Psycho1 Med 15:189-194, 1985 9. Woodhouse CRJ, Bockner S: Chronic abdominal pain: A surgical or psychiatric symptom? Br J Surg 66:348-349, 1979 10. Drossman DA: The patient with chronic undiagnosed abdominal pain. Hosp Pratt 2:22-29, 1986 11. Gomez J, Dally I’: Psychologically mediated abdominal pain in surgical and medical outpatient clinics. Br Med J 1:1451-1453, 1977 12. MacDonald AJ, Bouchier IAD: Non-organic gastrointestinal illness: A medical and psychiatric study. Br J Psychiatry 136:276-283, 1980 13. Eisendrath SJ, Way LW, Ostroff JW, Johnson CA: Identification of psychogenic abdominal pain. Psychosomatics 27(10):705-712, 1986 14. Drossman DA: Patients with psychogenic abdominal pain. 6 years’ observation. Am J Psychiatry 139:15491557, 1982 15. Creed F, Guthrie E: Psychological treatment of the irritable bowel syndrome: A review. Gut 30:1989
