Treatment of Recurrent Abdominal Pain: Components Analysis of Four Treatment Protocols

Background: Recurrent abdominal pain (RAP) affects up to 34% of the world's population of children. Medical management has been limited, but behavioral strategies have been shown to be effective. In this study several components of published treatment protocols were adapted and/or improved and then compared using a pretest-posttest control group design.

Cited Here...: Sixty-four children and teenagers (mean age, 9.75 ± 2.46 years) with diagnosed recurrent abdominal pain were randomly assigned to four groups: 1) fiber-only comparison group; 2) fiber and biofeedback-assisted cultivated low arousal; 3) fiber, biofeedback, and cognitive-behavioral interventions; and 4) fiber, biofeedback, cognitive-behavioral, and parental support. Participants were treated over 8 weeks in individual sessions. Biofeedback was supplied using small thermal devices.

Cited Here...: All groups showed improvement in self-reported pain, even the fiber-only comparison group; however, the active treatment groups showed significantly more improvement before and after than the fiber-only comparison group (fiber only comparison group pain reduction at 79%; fiber and biofeedback at 100%; fiber, biofeedback, and cognitive-behavioral at 94%; fiber, biofeedback, cognitive-behavioral, and parental support at 93%).

Conclusions: This suggests that any of the active treatment protocols assessed in this investigation work better than established treatments that have been reported in the literature. Because the addition of cognitive and parental support components did not seem to increase treatment effectiveness, it is concluded that increased fiber with biofeedback-assisted cultivated low arousal was effective and efficient as a treatment modality.

Recurrent abdominal pain (RAP) can be defined as recurring episodes of abdominal pain severe enough to interfere with a child's usual activities but not caused by an identifiable organic disease (¹, p. 306). Minimal criteria for patient inclusion in studies of RAP include at least three bouts of pain severe enough to affect activities during a period of not less than 3 months, with episodes continuing in the year preceding the examination ⁽²⁾.

Recurrent abdominal pain is believed to be the most common of pediatric gastrointestinal disorders ⁽³⁾. It affects up to 34% of the world's population of children and teenagers ⁽⁴⁾. It can take many forms; is often described as periumbilical or midepigastric; rarely awakens the patients at night; frequently bears no consistent association with meals, stress, or bowel movements; may last from a few minutes to more than an hour; and may vary in frequency from once a month or so to several episodes per day ⁽⁵⁾.

It is considered a benign (i.e., not associated with terminal illness) pain syndrome in 90% to 95% of these children ^(6,7). The recurring nature of this disorder can result in increased school absences, use of medical care resources, and family disruption ⁽⁸⁾. Although the cause of RAP remains unclear, it is important to note that the absence of a definitive cause does not mean that the pain is not real or all in the child's head⁽⁶⁾. Both psychological (e.g., stress, operant conditioning, modeling, depression, family enmeshment, somatization disorder) and physiological (e.g., autonomic instability, lactose intolerance, constipation, gut motility) factors have been implicated ⁽⁹⁾.

Although there are several reports on the persistence of pain complaints, the cause and natural course of RAP is largely unknown ⁽¹⁰⁾. Several investigators believe RAP in childhood is the pediatric equivalent of adult irritable bowel syndrome (IBS) ^(11-13). It has been suggested that it is a sign of our ignorance that so many diverse explanations can be current ⁽¹⁴⁾. Frank malingering is uncommon with this disorder, and it is exceedingly rare that RAP is imaginary ⁽¹⁵⁾.

Researchers in a number of previous studies have supported the efficacy of cognitive and behavioral interventions designed to alter the child's coping repertoire and mother-child interaction. Sanders et al. ^(1,16) have shown that a multicomponant intervention that includes . . . provision of an explanation of RAP and a rationale for pain management procedures; contingency management training for parents; and self management training for children (¹,p.309) was superior to standard pediatric care in reducing pain symptoms. Based on a regression analysis, the authors concluded that the results supported the cognitive-behavioral family model of pain management, . . . which focuses on changing both children's coping strategies to manage their pain and parents caregiving strategies (¹,p.312).

In this study, several components (i.e., increased dietary fiber, biofeedback-assisted cultivated low arousal, cognitive-behavioral interventions, and/or parental support) of published treatment protocols ^(1,16,17) were adapted or improved and then compared using a pretest-posttest control group design. Because predominant use of white patients in comparison with other ethnic groups in past RAP studies is suspected of contributing to contradictory results ^(12,18,19), this study was conducted in an ethnically diverse location. It has been suggested that conflicting results in RAP studies could be due to differences in the selection of patients ⁽¹²⁾. For example, whereas Anglo-Saxon, Irish, Polish, and Danish RAP populations are described as having a low prevalence of lactose malabsorption (LM), 75% of Italian children with RAP were found to be lactose malabsorbers ⁽¹⁹⁾. This is in contrast to the 9% found to have LM in Hungry ⁽²⁰⁾. Because of this, there is a need to conduct research in patients of different ethnic and cultural groups ⁽¹⁸⁾. Because dietary fiber has been shown to be more effective than placebo in at least one controlled trial ⁽²¹⁾, a fiber-only comparison group was used as the minimal treatment condition.

In the current study, we sought to extend the literature on RAP by further clarification of the necessary and/or sufficient treatment components. Detailed treatment protocols were used in this controlled treatment outcome study with emphasis on the reduction and/or complete elimination of RAP symptoms, taking into consideration that most physiologic disorders have psychological sequelae ⁽²²⁾.

MATERIALS AND METHODS

Participants contacted the researchers directly in response to media publicity, public announcements, leaflets, hearing of the study by word of mouth, or direct medical referral from their health care professionals. Before admission to the study, each individual underwent medical evaluation and had medically diagnosed RAP. Participants consisted of 64 children and teenagers in the southern California area (26 boys, 38 girls). All participants' parents or guardians were required to give their consent for inclusion in the study of the children under their care.

Patients were randomly assigned to one of the four groups: 16 in two active treatment conditions, 17 in one active treatment condition, and 15 in the fiber-only comparison group condition (N = 61 after attrition).

More than half the participants were white, with many identifying themselves as multiracial. Results in χ² analyses revealed that ethnicity and gender were equally distributed across the four groups, suggesting group equivalency. At the beginning of the study, age of the participants ranged from 4 to 18 years. There were no significant differences in age in the four groups.

This treatment outcome study implemented a 4 × 2 randomized factorial design: an expanded pretest-posttest control group design. It provided the basis for a pretest-posttest components analysis of the increased dietary fiber, cognitive-behavioral interventions, biofeedback-assisted cultivated low arousal, and parental support treatment of RAP. Increased dietary fiber (i.e., 10+ g per day per child) was included in all four groups (i.e., three active treatment conditions and one fiber-only comparison group) as a minimal requirement of inclusion in the study. Fiber products (i.e., cookies and bars) were supplied by researchers.

The four treatment groups were as follows: 1) increased dietary fiber-only comparison group; 2) increased dietary fiber and biofeedback-assisted cultivated low arousal; 3) increased dietary fiber, biofeedback-assisted cultivated low arousal, cognitive-behavioral interventions; and 4) increased dietary fiber, biofeedback-assisted cultivated low arousal, cognitive-behavioral interventions, and parental support. Each group's treatment protocol was detailed in a separate treatment manual based on an adaptation and improvement of a widely used and government-sponsored Australian research program ⁽¹⁸⁾ (The use and reproduction of these materials were with written permission from Sanders, September 1, 1992 and March 14, 1993.) In the active treatment conditions, hand temperature levels of the children were monitored in an effort to establish that they actually learned the procedures by cognitively following and implementing the instructions delivered by the researchers. This thermal biofeedback and monitoring was accomplished using a Human Measurement Systems Hand Temperature Treatment Clock and Thermometer, model NAW-882EXL (Monrovia, CA, U.S.A.).

The RAP symptomatology was indicated by levels of experienced pain, use of medical services, and use of medications. The RAP was measured by the Parents' Pain Observation Record (POR) and the Child's Pain Diary (CPD). Uses of medical services and medications were measured by the Record of Health Care Utilization, Form 1 (RHCU-F1); Record of Health Care Utilization, Form 2 (RHCU-F2); and the Medication Record (MR). School attendance was measured by the Record of School Attendance, Forms 1 and 2 (RSA-F1, RSA-F2). These measures have been widely used in RAP outcome studies and have been shown to have adequate reliability and validity ^(1,18).

Spot checks were conducted on 10% of the children's school records of attendance before and after the study. Evaluations of the participants' medical records were also conducted on the same 10% to ascertain use of medical services and availability of medications. Parents were informed of the researchers' plans to enlist the use of these records in the study. They were not informed that the inspection would only include 10% of the records.

After screening procedures and random assignments, as detailed, were completed, participants were treated during a period of approximately 8 weeks. They were seated in chairs appropriate for their physical size. At the initial psychological assessment, an explanation of the study and an overview of the treatment process were given as outlined in the appropriate Treatment Manual.

The multicomponent treatment model's first meeting began with the referral procedure and the initial psychological assessment, which included an initial interview, provisions of monitoring, assessment questionnaires, and informing participants of their random assignments to treatment conditions. Treatment session 1 reviewed baseline, outlined treatment, explained pain-related behavior, defined pain, and encouraged development of personal relaxation techniques. In treatment 2, discrimination training was introduced, reinforcement schedules were set up, rewards decided on, and distraction techniques presented. Relaxation training, coping statements, and self-management were the focus of treatment 3. Treatment 4 covered abbreviated and additional relaxation training, refined the coping statements and self-management techniques, and introduced self talk. Treatment 5 refined skills acquisition and integration, identified high-risk situations, and introduced relapse prevention. Treatment 6 was used for a general review and further relapse prevention. The last or eighth meeting dealt with termination and debriefing issues.

Biofeedback was supplied using small thermal devices. Digital temperature readings during each treatment session were recorded as a manipulation check. These measurements allowed for the verification of participants' acquisition and ability to follow the biofeedback-assisted cultivated low arousal, progressive muscle relaxation, and/or self-control of pain instructions. All participants experienced an increase in digital temperature after treatment interventions. These specific changes in digital temperature are reported in Results.

Furthermore, to insure that the participants in the cognitive condition grasped the cognitive interventions, they were instructed to role-play them by teaching these interventions to the experimenter and then to their parents. Repeated instructions were given until each child could demonstrate complete competency in this role playing. Many participants especially enjoyed role-playing the Pain Behavior Flow Charts, which addressed verbal complaints, nonverbal complaints, and requests for medications. Behavior contracts received mixed reactions.

RESULTS

Group Equivalence

The four groups were compared for equivalence of gender, ethnicity, age, digital temperature, symptom self-ratings, and parental ratings. The χ² analyses for nominal data and analyses of variance for continuous data showed no significant differences among the groups. It was therefore concluded that the random assignment was successful.

Manipulation Check

For the three active treatment groups (all using digital temperature biofeedback), temperature levels within sessions were analyzed. All groups showed significant within-session increases indicating successful self-regulation of peripheral temperature. No differences between the groups were significant, nor was a group defined by time interaction.

Test of the Main Hypotheses

The means and standard deviations are shown in Tables 1, 2, and 3 and are partially pictured in Figures 1 and 2. The three active treatment groups were first compared on the outcome measures (self-reported pain, parent observations, medication use, health care utilization, and school attendance). A series of 3 (groups) × 2 (time) analyses of variance showed no significant main effects for group and no interaction. Main effects for pre-versus posttreatment were found for self-reported pain (F_1,43 = 117.19, P < 0.001); parents' observation of the child's asking for help (F_1,43 = 7.64, P < 0.01), report of pain (F_1,43 = 22.83, P < 0.001), vocal protest (F_1,43 = 6.53, P < 0.02), other behavior (F_1,43 = 6.55, P < 0.02), RAP medication reduction (F_1,43 = 11.86, P < 0.001), and school absences (F_1,43 = 8.53, P < 0.01). Given these results and that the effect sizes for the group by pre-versus postinteraction were quite small, it appears as though the three treatment groups produced improvement but that the improvement did not differ from one group to another.

Table 1	Table 2	Table 3
Fig. 1	Fig. 2

Subsequent analyses involved planned comparisons between the combined treatment groups and the fiber-only comparison group. The combined groups showed more improvement than the fiber-only comparison group on self-reported pain (F_1,59 for interaction = 10.20, P = 0.002). The fiber-only group improved significantly in school absences for RAP (t¹⁴ = 3.36, P = 0.005) and school absences for other reasons (t¹⁴ = 2.23, P = 0.043), but in no other measures. Before versus after interaction, the combined groups improved in school absences (for RAP;t⁴⁵ = 7.26, P < 0.001); school absences, other (t⁴⁵ = 7.97, P < 0.001); asking for help (t⁴⁵ = 2.81, P = 0.007); parents' observation of pain (t⁴⁵ = 4.73, P < 0.001); verbal protest (t⁴⁵ = 2.61, P = 0.012); parents' observation of RAP symptoms (t⁴⁵ = 2.84, P = 0.007); medical records for RAP (t⁴⁵ = 2.18, P = 0.035); and record of health care utilization (for RAP;t⁴⁵ =2.43, P = 0.019). For self-reported pain, 33 (72%) of 46 of treatment participants reported elimination of pain, whereas this was true for only 1 (7%) of the 14 fiber-only comparison group members. Decreased pain was seen in an additional 26% of treatment participants and in 79% of the fiber-only comparison group. Finally, 2 (4%) of the treated participants reported increased pain compared with 3 (21%) of the fiber-only comparison group. Using this classification, the treated groups differed significantly from the fiber-only comparison group (χ² = 21.74, P < 0.01).

Additional Analyses

The correlation of reported use of dietary fiber with pain reduction, especially in the last week of treatment, was evaluated (r₅₉ = -0.5, P < 0.001). The results indicate a relationship between increased fiber intake and reduction of symptoms. No significant correlations with temperature increase and symptom reduction were found.

Correlations between temperature gains (for those practicing hand warming in the biofeedback conditions) and symptom reduction were not found to be significant. Thus the degree to which the patient was able to warm his or her hands was not associated with symptom reduction.

DISCUSSION

The present findings replicate those in previous work ^(1,18,19), in that a biobehavioral treatment protocol was effective in RAP treatment. All but 2 of the 47 treatment participants had a decrease in or elimination of pain. Anecdotal evidence matched the data, in that most children reported positive coping techniques that they had begun to use to manage oncoming gastrointestinal pain. Finding the active ingredient within the protocol was more difficult. There was a mild trend for the combination group to fare worse than those with the simpler treatments. It may be that this amount of material presented in a short protocol is too much for adequate learning. The biofeedback group seemed to do well without the explicit cognitive component. However, using the digital temperature method as an alternative coping technique incorporates many of the cognitive elements. In any case, this very simple, inexpensive protocol could be used easily in medical settings without extensive staff training.

The use of fiber, although common in RAP treatment, has not been extensively studied. The fiber-only comparison group seemed to show some improvements. Without a waiting-list control group, we could not determine whether this was a placebo or a nonspecific effect. This determination awaits further research.

It appears that these results together with those mentioned warrant larger trials in pediatric treatment centers. Because the cost of the protocol is low and could be accomplished in groups, medical offsets could be favorable.

The treatment successes seem to indicate mind-gut relationships in children similar to those identified in adult IBS. Further research is needed to determine the mechanisms of pain and bowel disturbance ⁽²³⁾. Hyperalgesia in the gut, autonomic dysfunction, and central hyperalgesia have all been implicated in recent IBS models and are probably similar in RAP. If these models were shown to be applicable, it would force a shift in explanatory models that posit the dysfunction in strict cognitive-behavioral terms.

Acknowledgments:

The authors thank research assistants Maridee Hunter and Nancy Shafer who assisted in collating participants' packets, scoring instruments, and entering preliminary data.