Pica and Rumination Questionnaire (CuPRu)

Abstract

The Pica and Rumination Questionnaire (known by its Spanish acronym CuPRu, Cuestionario de Pica y Rumiación) is an 18-item self-report psychometric instrument designed to identify and evaluate behavioral manifestations, cognitive features, and somatic symptoms associated with pica and rumination disorder. Developed and psychometrically validated by Medina-Tepal, Vázquez-Arévalo, Calleja-Bello, and Mancilla-Díaz (2023) at the National Autonomous University of Mexico (UNAM), the CuPRu addresses a critical diagnostic and epidemiological void in the assessment of feeding and eating disorders among adolescents and young adults. Historically, both pica and rumination were conceptualized primarily as pediatric pathologies or conditions exclusive to individuals with severe intellectual and neurodevelopmental disabilities. Consequently, psychometrically robust, validated screening tools tailored for community, non-clinical, and clinical youth populations have been virtually absent in Spanish-speaking regions.

The scale development began with an extensive pool of 45 initial items derived from diagnostic criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and expert panel evaluation. Following empirical testing in a sample of Mexican adolescents and young adults, exploratory and confirmatory factor analyses refined the instrument to an 18-item, four-factor structural model: (1) Regurgitation (5 items), (2) Gastrointestinal Symptoms (4 items), (3) Consumption of Nonfood/Raw or Unprocessed Substances (4 items), and (4) Pica Symptoms (5 items). Items are scored on a five-point Likert-type scale ranging from 0 to 4. Psychometric evaluation demonstrated high internal consistency, yielding a Cronbach’s alpha coefficient of 0.85 and a McDonald’s omega coefficient of 0.93. The four-factor structure accounted for 48.35% of the total variance, exhibiting acceptable confirmatory goodness-of-fit indices (CMIN = 2.41, GFI = 0.92, AGFI = 0.89, CFI = 0.93, RMR = 0.063, RMSEA = 0.064). Item Response Theory (IRT) parameters revealed adequate item discrimination indices ($a > 1.0$) and balanced difficulty thresholds across the latent continuum. The CuPRu represents a significant advance for clinical screening, epidemiological research, and differential diagnosis within clinical psychology, adolescent medicine, and psychiatry.

Keywords

Pica, Rumination Disorder, CuPRu, Eating Disorders, Adolescents, Young Adults, Regurgitation, Gastrointestinal Symptoms, Psychometrics, Item Response Theory, DSM-5

Authors

The Cuestionario de Pica y Rumiación (CuPRu) was constructed and validated by a team of clinical psychologists and researchers specializing in eating behaviors and nutritional psychopathology affiliated with the Universidad Nacional Autónoma de México (UNAM):

• Karla Areli Medina-Tepal — Division of Research and Postgraduate Studies, Facultad de Estudios Superiores (FES) Iztacala, Universidad Nacional Autónoma de México (UNAM), Tlalnepantla, Estado de México, Mexico. Email: [email protected].
• Rosalía Vázquez-Arévalo — Eating Disorders and Nutrition Research Group, Facultad de Estudios Superiores (FES) Iztacala, Universidad Nacional Autónoma de México (UNAM), Tlalnepantla, Estado de México, Mexico.
• Nazira Calleja-Bello — Facultad de Psicología, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.
• Juan Manuel Mancilla-Díaz — Eating Disorders and Nutrition Research Group, Division of Research and Postgraduate Studies, Facultad de Estudios Superiores (FES) Iztacala, Universidad Nacional Autónoma de México (UNAM), Tlalnepantla, Estado de México, Mexico.

Purpose

The primary clinical and empirical purpose of the Cuestionario de Pica y Rumiación (CuPRu) is to systematically measure, differentiate, and quantify the behavioral, cognitive, emotional, and physical indicators of pica and rumination syndrome among adolescents and young adults. Historically, nosological classifications such as the DSM-IV relegated pica and rumination disorder to the diagnostic chapter of “Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence.” This classification created a pervasive clinician bias, leading many healthcare professionals to assume that these conditions do not manifest in cognitively intact adolescents and adults. However, the restructuring in the DSM-5 and ICD-11 placed these conditions alongside anorexia nervosa, bulimia nervosa, binge eating disorder, and avoidant/restrictive food intake disorder (ARFID). This shift underscored the need for standardized instruments capable of assessing pica and rumination across the entire developmental lifespan.

In clinical practice, the CuPRu serves several diagnostic and therapeutic functions:

• Differential Diagnosis: Differentiating rumination disorder from medical gastrointestinal illnesses such as gastroesophageal reflux disease (GERD), gastroparesis, achalasia, and cyclic vomiting syndrome, as well as distinguishing non-purposive postprandial regurgitation from compensatory purging behaviors in bulimia nervosa.
• Severity and Frequency Quantification: Assessing the frequency of regurgitation, the specific physical and affective triggers (e.g., emotional stress, autonomic arousal), and subsequent behaviors such as re-chewing, reswallowing, or spitting out food boluses.
• Pica Ingestion Profiling: Identifying the consumption of non-nutritive, non-food substances (e.g., earth, chalk, paper, ice, metal, plastic) versus the problematic consumption of raw, unprocessed food items (e.g., raw flour, uncooked rice, dry pasta, potato starch, large volumes of unrefined salt or spices), which carry significant clinical and nutritional risks.
• Cognitive and Affective Burden: Measuring the emotional distress, social avoidance, shame, and obsessive preoccupation that often accompany concealed pica or rumination habits.
• Treatment Outcome Monitoring: Providing a sensitive, standardized metric for assessing therapeutic interventions such as habit reversal training (HRT), diaphragmatic breathing protocols, biofeedback, and cognitive-behavioral therapy (CBT).

From an epidemiological and public health perspective, the CuPRu addresses the significant underreporting of pica and rumination. Individuals struggling with these disorders frequently conceal their behaviors due to embarrassment or fear of stigmatization. By offering a standardized self-report questionnaire, the CuPRu enables researchers to establish reliable prevalence estimates, explore comorbidities with nutritional deficiencies (such as iron-deficiency anemia and zinc deficiency), and identify cultural, environmental, or familial factors influencing eating pathologies.

Psychological Construct

The CuPRu operationalizes a multidimensional construct encompassing two distinct yet frequently overlapping feeding and eating disorders: Rumination Disorder and Pica. While distinct in their clinical presentations, these behaviors share common features, including covert behavioral maintenance, atypical oral engagement with substances, secondary gastrointestinal distress, and heightened emotional dysregulation. The 18 items of the CuPRu are organized into four interrelated subscales:

1. Regurgitation (Regurgitar)

This subscale evaluates the core physiological and behavioral features of rumination syndrome. In clinical psychology and neurogastroenterology, rumination is defined as the effortless, repetitive, postprandial return of recently ingested food into the oral cavity, which is not preceded by retching or accompanied by the classic nausea associated with involuntary vomiting. The CuPRu measures the frequency of food returning to the mouth, the behavioral sequence following regurgitation (specifically whether the individual re-chews, re-swallows, or expels/spits out the regurgitated matter), the spontaneous occurrence of regurgitation without apparent physiological cause, and the exacerbation of regurgitation episodes under acute emotional stress, anxiety, or cognitive tension.

2. Gastrointestinal Symptoms (Síntomas Gastrointestinales)

This dimension assesses the somatic symptoms and visceral discomfort associated with disordered ingestion and regurgitation. It targets sensations of epigastric burning, retrosternal heartburn (pyrosis), abdominal distension, severe bloating (feeling as though the stomach is inflated with gas), and the presence or absence of secondary nausea. By measuring these physical markers, this subscale helps clinicians assess gastrointestinal distress and aids in the differential diagnosis between primary functional rumination and somatic conditions such as functional dyspepsia or acid reflux disease.

3. Consumption of Nonfood/Raw or Unprocessed Substances (Consumo de Sustancias No Comestibles, Crudas o No Procesadas)

This objective behavioral dimension captures the specific range, diversity, and operational frequency of inappropriate ingestion. Rather than evaluating subjective attitudes, this subscale acts as a quantitative inventory of the number and types of non-nutritive materials consumed (such as soil, clay, chalk, paper, cloth, hair, or ashes) as well as raw, unprocessed culinary materials consumed compulsively outside of normative culinary practices (such as raw starches, uncooked grains, large quantities of salt, or ice/pagophagia). This distinction aligns with contemporary clinical literature recognizing that high-frequency ingestion of uncooked ingredients can result in similar metabolic, mechanical, and gastrointestinal complications as classic pica.

4. Pica Symptoms (Síntomas de Pica)

This subscale assesses the cognitive, affective, and psychological components of pica. Drawing from cognitive-behavioral formulations of eating disorders and impulse-control problems, this dimension measures the subjective pleasure or reward derived from consuming non-nutritive or raw substances, cognitive preoccupation and intrusive cravings, the degree of shame or concealment surrounding the behavior, and persistent ingestion despite clear awareness of negative medical consequences (e.g., intestinal blockages, dental fractures, toxic ingestions, or systemic infections).

Theoretical Framework

The conceptual framework of the CuPRu is grounded in the operational criteria of the DSM-5 and ICD-11, integrated with operant conditioning theory, interoceptive processing models, and cognitive-behavioral conceptualizations of feeding and eating disorders.

Diagnostic Evolution (DSM-5 and ICD-11)

Historically, the psychiatric community categorized pica and rumination as developmental or pediatric conditions. The release of the DSM-5 in 2013 removed the developmental age restriction, establishing that these disorders can emerge and persist across childhood, adolescence, and adulthood. Rumination disorder requires the repeated regurgitation of food over a period of at least one month, not attributable to an associated gastrointestinal or medical condition, and not occurring exclusively during the course of anorexia nervosa, bulimia nervosa, ARFID, or binge-eating disorder. Similarly, pica requires the persistent eating of non-nutritive, non-food substances over at least one month that is developmentally inappropriate and not supported by culturally sanctioned or social norms. The CuPRu was designed to capture these criteria directly within self-report metrics suitable for adolescent and adult populations.

Operant Conditioning and Habit Reversal Models

From a behavioral psychology perspective, rumination is largely conceptualized as an involuntary-turned-conditioned physical habit maintained through automatic reinforcement. In many individuals, subtle somatic cues or visceral fullness following meals trigger an unconditioned or conditioned abdominal wall contraction coupled with lower esophageal sphincter relaxation. While the initial return of gastric contents may be experienced as uncomfortable, the subsequent motor action—such as oral manipulation, re-chewing, or sensory stimulation—often acts as a form of automatic positive reinforcement. Concurrently, the alleviation of postprandial abdominal fullness or emotional tension functions as negative reinforcement.

Pica behaviors often follow a similar reinforcement model. The consumption of non-food textures (such as the crunch of ice, chalk, or clay) provides sensory, tactile, and gustatory stimulation, while also functioning as an emotional coping mechanism to reduce stress, anxiety, or boredom.

Gastrointestinal Interoception and Somatic Feedback

The inclusion of gastrointestinal symptom items aligns with neurogastroenterological research into the gut-brain axis and visceral interoception. Patients with rumination syndrome frequently demonstrate altered sensory thresholds in the proximal stomach, displaying gastric hypersensitivity where normal postprandial gastric distension is misinterpreted as discomfort, prompting habitual abdominal contractions. Distinguishing between functional rumination and somatic gastrointestinal symptoms is critical for effective differential diagnosis.

Validity

The psychometric validation of the CuPRu was conducted following rigorous methodological guidelines, including content validation, construct validation through factor analysis, and Item Response Theory (IRT) modeling.

Content Validity

The initial pool of 45 items was submitted to an independent expert panel consisting of clinical psychologists, psychiatrists, and psychometricians with specialized expertise in feeding and eating pathologies. Item evaluation utilized Aiken’s V coefficient to assess representativeness, conceptual relevance, semantic clarity, and cultural appropriateness for Mexican youth. A strict statistical threshold of $V ge 0.85$ was established as the criterion for item retention. All items retained in the provisional scale met or exceeded this cutoff, demonstrating strong expert consensus and establishing robust content validity.

Construct Validity

Construct validity was established through sequential exploratory and confirmatory factor analyses. The exploratory factor analysis (EFA) demonstrated that an 18-item, four-factor model provided the most theoretically coherent and parsimonious solution. Confirmatory Factor Analysis (CFA) cross-validated this 18-item structural model in an independent sample of adolescents and young adults. The overall model fit was evaluated using standard goodness-of-fit indices:

• CMIN/DF (Normed Chi-Square): $2.41$ (well within the recommended range of $< 3.0$, indicating acceptable fit).
• Goodness-of-Fit Index (GFI): $0.92$ (meeting the standard $ge 0.90$ benchmark).
• Adjusted Goodness-of-Fit Index (AGFI): $0.89$ (approaching the optimal $ge 0.90$ threshold).
• Comparative Fit Index (CFI): $0.93$ (exceeding the standard $ge 0.90$ cutoff for acceptable structural fit).
• Root Mean Square Residual (RMR): $0.063$ (reflecting low residual covariance).
• Root Mean Square Error of Approximation (RMSEA): $0.064$ ($90% \text{ CI } [0.055, 0.073]$, demonstrating acceptable model approximation error, below the standard $0.08$ threshold).

Collectively, the four latent factors accounted for 48.35% of the total cumulative variance, confirming that the 18 items reliably capture the underlying latent constructs of pica and rumination.

Reliability

The reliability of the CuPRu was evaluated through internal consistency analyses utilizing both classical test theory (Cronbach’s alpha) and latent variable modeling (McDonald’s omega). Because Cronbach’s alpha relies on the assumption of tau-equivalence (equal factor loadings across items), which is rarely met in multidimensional psychological inventories, McDonald’s omega was calculated to provide a more accurate estimate of composite reliability.

• Overall Cronbach’s Alpha ($\alpha$): $0.85$, reflecting high internal consistency across the total 18-item instrument.
• Overall McDonald’s Omega ($\omega$): $0.93$, demonstrating strong structural reliability and minimal measurement error across the composite scale.

Subscale reliability analyses demonstrated satisfactory internal consistency across the four dimensions:

• Regurgitation Subscale: Demonstrated high item-total correlations, with individual factor loadings exceeding $0.60$ and subscale alpha values above $0.80$.
• Gastrointestinal Symptoms Subscale: Displayed adequate internal consistency, reflecting reliable covariance among somatic complaints.
• Consumption of Nonfood/Raw Substances Subscale: Maintained acceptable reliability indices, capturing variability across different types of ingested substances.
• Pica Symptoms Subscale: Displayed strong reliability ($lpha > 0.82$), confirming consistent measurement of affective, cognitive, and behavioral indicators of pica.

Factor Analysis

The psychometric architecture of the CuPRu was identified and confirmed using a combination of exploratory factor analysis, confirmatory structural equation modeling, and Item Response Theory (IRT).

Factor Structure and Loadings

During the exploratory phase, principal axis factoring with oblique rotation was conducted on the initial item pool. Items exhibiting cross-loadings greater than $0.30$ across multiple factors, low communalities ($h^2 < 0.30$), or primary factor loadings below $0.40$ were systematically eliminated. This process reduced the scale from 45 items to an 18-item configuration across four distinct factors, accounting for 48.35% of the total variance:

• Factor 1: Regurgitation (5 items): Captures food return, re-chewing, re-swallowing, spitting out, spontaneous regurgitation, and stress-induced episodes.
• Factor 2: Gastrointestinal Symptoms (4 items): Captures heartburn/acidity, bloating, abdominal distension, and associated nausea.
• Factor 3: Consumption of Nonfood/Raw Substances (4 items): Quantifies the number, frequency, and diversity of non-food items and raw/unprocessed substances consumed.
• Factor 4: Pica Symptoms (5 items): Measures subjective pleasure, intrusive thoughts, shame, and continued consumption despite known health risks.

Item Response Theory (IRT) Calibration

To examine item-level functioning across different levels of the underlying latent trait ($\theta$), the authors conducted an IRT calibration using Samejima’s Graded Response Model (GRM). The analysis yielded two key psychometric insights:

• Item Discrimination ($a$ parameter): All 18 items demonstrated strong discrimination parameters, with all $a$ values exceeding $1.0$. This indicates that each item effectively distinguishes between individuals with low versus high levels of the target feeding pathology.
• Item Difficulty / Location ($b$ parameters): The threshold parameters for the four response categories across the 18 items fell consistently within the standard range of $-3.0$ to $+3.0$. Items in the Pica Symptoms and Regurgitation subscales exhibited higher positive threshold values, indicating that endorsement of high-severity options corresponds to elevated levels of clinical pathology.

Instrument / Measurement Tool

The CuPRu is a standardized, self-report psychometric instrument. Below are its structural and administrative characteristics:

• Instrument Name: Cuestionario de Pica y Rumiación (CuPRu) [Pica and Rumination Questionnaire].
• Original Authors: Karla Areli Medina-Tepal, Rosalía Vázquez-Arévalo, Nazira Calleja-Bello, and Juan Manuel Mancilla-Díaz (2023).
• Administration Format: Individual or group administration; available in paper-and-pencil or computerized/digital formats.
• Target Population: Adolescents (ages 12–17) and young adults (ages 18–29); also applicable across general adult clinical populations.
• Total Item Count: 18 items.
• Subscale Breakdown:
  • Regurgitation: 5 items
  • Gastrointestinal Symptoms: 4 items
  • Consumption of Nonfood/Raw or Unprocessed Substances: 4 items
  • Pica Symptoms: 5 items
• Response Scale: 5-point Likert-type scale scored from 0 to 4:
  • 0 = Nunca (Never)
  • 1 = Raras veces (Rarely)
  • 2 = Algunas veces (Sometimes)
  • 3 = Frecuentemente (Frequently)
  • 4 = Muy frecuentemente (Very frequently)
• Scoring Procedures:
  • Subscale scores are calculated by summing the endorsed values of their respective items.
  • A Total CuPRu Score can be obtained by summing all 18 items (theoretical score range: 0 to 72), where higher scores indicate greater symptom severity and behavioral frequency.
  • Subscales can be analyzed independently to profile specific rumination or pica symptoms.
• Estimated Completion Time: Approximately 5 to 10 minutes.

Permissions & Fee and Test Year

The Cuestionario de Pica y Rumiación (CuPRu) was developed and published in 2023. In accordance with open-science initiatives supported by the Universidad Nacional Autónoma de México (UNAM) and the Revista de Psicología Clínica con Niños y Adolescentes:

• Permissions: The CuPRu is available for academic, clinical, and non-commercial scientific research without licensing fees. Researchers and clinicians may utilize the instrument provided appropriate citation is given to Medina-Tepal et al. (2023).
• Commercial Use: Commercial use, unauthorized distribution, or incorporation into fee-based software platforms requires formal written permission from the corresponding authors and the copyright-holding institution.
• Fees: Free of charge ($0.00) for research and non-profit educational/clinical applications.
• Correspondence Contact: Karla Areli Medina-Tepal, Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla, Estado de México, Mexico. Email: [email protected].

References

• American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). American Psychiatric Publishing. https://doi.org/10.1176/appi.books.9780890425596
• Bryant-Waugh, R., Markham, L., Kreipe, R. E., & Walsh, B. T. (2010). Feeding and eating disorders in childhood. International Journal of Eating Disorders, 43(2), 98–111. https://doi.org/10.1002/eat.20795
• Hartmann, A. S., Poulain, T., Vogel, M., Hiemisch, A., Kiess, W., & Hilbert, A. (2018). Prevalence of pica and rumination behaviors in German children. European Child & Adolescent Psychiatry, 27(11), 1499–1508. https://doi.org/10.1007/s00787-018-1149-8
• Medina-Tepal, K. A., Vázquez-Arévalo, R., Calleja-Bello, N., & Mancilla-Díaz, J. M. (2023). Construcción y validación del Cuestionario de Pica y Rumiación (CuPRu) en adolescentes y adultos jóvenes mexicanos [Construction and validation of the Pica and Rumination Questionnaire in Mexican adolescents and young adults]. Revista de Psicología Clínica con Niños y Adolescentes, 10(2), 1–10. https://doi.org/10.33776/rpcna.v10.i2.4632
• Murray, H. B., Juarascio, A. S., Di Lorenzo, C., Drossman, D. A., & Thomas, J. J. (2019). Diagnosis and treatment of rumination syndrome: A critical review. The American Journal of Gastroenterology, 114(4), 562–578. https://doi.org/10.14309/ajg.0000000000000060
• Stange, K. C. (2011). Pica and rumination. In J. Alexander & A. B. Treasure (Eds.), A collaborative approach to eating disorders (pp. 273–284). Routledge.
• World Health Organization. (2019). International statistical classification of diseases and related health problems (11th ed.). World Health Organization. https://icd.who.int/

Items of the Scale