| Level I | Good quality evidence |
Systematic review of RCTs with consistent findings High quality individual RCT |
| Level II |
Limited quality patient orientated evidence |
Systematic review of lower quality studies or studies with inconsistent findings Low quality clinical trial Cohort studies Case-control studies |
| Level III | Other |
Consensus guidelines, extrapolations from bench research, usual practice, opinion, disease-oriented evidence (intermediate or physiologic outcomes only), or case series |
[20] Whole bowel irrigation (with polyethylene glycol): Thanacoody R, Caravati EM, Troutman B, Hojer J, Benson B, Hoppu K et al. Position paper update: whole bowel irrigation for gastrointestinal decontamination of overdose patients. Clin Toxicol (Phila) 2015;53:5-12. https://www.ncbi.nlm.nih.gov/pubmed/25511637
Whole bowel irrigation (with polyethylene glycol): National Department of Health, Essential Drugs Programme: Paediatric Hospital Level STGs and EML, 2017. http://www.health.gov.za/