Journal articles
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5001845/ (free)
This very detailed review tells you everything you might ever need to know about irritable bowel syndrome.
https://www.nature.com/articles/nrgastro.2012.134/ (paid)
This very detailed review covers the pathophysiology and management of postoperative ileus.
https://pubmed.ncbi.nlm.nih.gov/33263938/ (free)
This open access review published in 2021 summarises the current understanding of the epidemiology, pathophysiology and diagnosis of chronic constipation.
https://pubmed.ncbi.nlm.nih.gov/33522079/ (free)
This open access review published in 2021 sets out the latest state of the art in the clinical management of chronic constipation.
https://pubmed.ncbi.nlm.nih.gov/23399525/ (paid)
This review provides further information on a number of rare neuromuscular diseases affecting the gastrointestinal tract for the interested reader.
https://pubmed.ncbi.nlm.nih.gov/27144630/ (free)
The Rome guidelines for functional anorectal disorders covers defecation disorders relevant to constipation (also has resources for faecal incontinence and chronic anal pain).