This study was performed at a tertiary referral center with a specialized CVS clinic. The study was approved by the Institutional Review Board (#2024H0003), and all participants provided written informed consent prior to study procedures. Participants received remuneration for their participation.

Study Population

All participants who were diagnosed with CVS based on Rome IV criteria were included in the study. Some participants had typical clinical features, but others had longer episodes that did not conform to the 7-day criteria as per Rome. A recent prospective study demonstrated that 13% had episodes lasting 7–10 days, 18% had episodes that last greater than 10 days, indicating that CVS episodes are not always consistently less than 7 days [16].

Inclusion criteria included the following: Age > 18 years, ability to read English and independently operate an iPad or home computer. Exclusion criteria included 1. Inability to voluntarily provide informed consent for the study (including vulnerable populations such as prisoners). 2. Other major GI problems such as inflammatory bowel disease, cirrhosis or medical problems like renal failure, cardiac failure, or liver cirrhosis.

Severity of CVS as mild or moderate/severe was defined based on current guidelines. This was defined based on both episode duration and frequency and duration and need for emergency department visits and/or hospitalization. Patients who had < 4 episodes a year, lasting < 2 days, with a quick recovery and without any ED visits or hospitalizations were classified as having mild CVS. Those with any of the following: 4 or more episodes a year, duration of episodes which last no more than 2 days and need for ED visits and/or hospitalizations were classified as having moderate-to-severe CVS [17].

Subject Recruitment

Potential participants with CVS were recruited through the CVS clinic and consecutively offered the opportunity to participate in the study. Potential participants were also contacted through an established CVS patient registry. An e-consent form was used to obtain informed consent. All questionnaires were completed using REDCap, a HIPAA-compliant online research platform that utilizes data encryption, safeguarding data from unauthorized access during transmission and storage, ensuring confidentiality and integrity of research data.

Clinical Data

All participants completed a standard CVS intake questionnaire that asked about disease characteristics, comorbidities, treatment, and response to treatment. This was reconciled with chart review and patient interview as needed if any discrepancies were noted.

Assessment ToolsPatient-Generated Subjective Global Assessment (PG-SGA)

The PG-SGA is a validated, comprehensive, multipart assessment used to determine malnutrition risk (PG-SGA-Short Form [SF]) and severity of a malnutrition diagnosis [15]. This is considered a 4-1 tool that can be used for screening, assessment, triage, and monitoring of interventions. It consists of two sections: a self-report questionnaire (boxes 1–4, also referred to as the PG-SGA-SF) and a professional evaluation (worksheets 1–5); each box/worksheet is individually scored and then totaled. Scores can range from 0 to 39, with higher numbers indicating a greater risk of malnutrition. Specifically, a score of 0–1 indicates no nutritional intervention required, 2–3 suggests the need for patient education or symptom management, 4–8 indicates moderate malnutrition and warrants RDN-led intervention, and ≥ 9 indicates severe malnutrition and signifies a critical need for urgent RDN-led intervention.

In addition, the professional evaluation using the PG-SGA classifies participants as well-nourished (A), moderately or suspected malnourished (B), or severely malnourished (C) [15].This assessment was performed by a RDN and integrated five domains: recent weight change, dietary intake, nutrition-impact symptoms, functional capacity, and physical examination findings. Overall nutritional status was determined based on the cumulative severity across these domains. All assessments were performed during the inter-episodic phase of a CVS episode. Those deemed well-nourished scored < 7 points while those with moderate-to-severe malnutrition had ≥ 7 points.

Cannabis Use Disorder Identification Test (CUDIT)

Cannabis use was assessed using the CUDIT-R, a validated tool used to screen for cannabis misuse [18]. This questionnaire consists of 8 questions that are each scored from 0 to 4 based on the response. A score > 12 indicates possible cannabis use disorder, and a score of 8–12 indicates hazardous cannabis use.

Malnutrition Screening Tool (MST)

The MST is a simple 2-item validated screening tool with a score of ≥ 2 indicating individuals who are at risk of becoming malnourished and who may benefit from an RDN assessment [19].

Food Security Questionnaire

The food security questionnaire is a standard 6-item questionnaire with households with scores of 0–1 characterized as food secure, while scores of 2–4 indicate low food security, and scores of 5–6 represent very low food security [19]

Statistical Analysis

Demographics and clinical characteristics were summarized and differences between the two groups (well-nourished vs. malnourished) based on RDN assessment were determined using Chi-square test or Fisher exact test for categorical variables, T test for continuous variables, and exact Wilcoxon test for count variables. Univariate logistic models were developed to test the associations between nutritional status and various demographic and clinical factors. Multivariable logistic models were then conducted. Variables added to the model were selected a priori and based on important clinic factors and univariate analyses. SAS Studio (SAS Institute Inc., Cary, NC) was used for all analyses. Two-sided tests were conducted, and p < 0.05 was considered statistically significant.