The gastrocolic reflex or gastrocolic response is a physiological reflex that controls the motility, or peristalsis, of the gastrointestinal tract following a meal. It involves an increase in motility of the colon consisting primarily of giant migrating contractions, or migrating motor complexes, in response to stretch in the stomach following ingestion and byproducts of digestion entering the small intestine.[1] Thus, this reflex is responsible for the urge to defecate following a meal. The small intestine also shows a similar motility response. The gastrocolic reflex's function in driving existing intestinal contents through the digestive system helps make way for ingested food.[2]

The reflex was demonstrated by myoelectric recordings in the colons of animals and humans, which showed an increase in electrical activity within as little as 15 minutes after eating. The recordings also demonstrated that the gastrocolic reflex is uneven in its distribution throughout the colon. The sigmoid colon is more greatly affected than the rest of the colon in terms of a phasic response, recurring periods of contraction followed by relaxation, in order to propel food distally into the rectum; however, the tonic response across the colon is uncertain. These contractions are generated by the muscularis externa stimulated by the myenteric plexus.[1] When pressure within the rectum becomes increased, the gastrocolic reflex acts as a stimulus for defecation. A number of neuropeptides have been proposed as mediators of the gastrocolic reflex. These include serotonin, neurotensin, cholecystokinin, prostaglandin E1, and gastrin.[1][3]

Coffee can induce a significant response, with 29% of subjects in a study reporting an urge to defecate after ingestion, and manometry showing a reaction typically between 4 and 30 minutes after consumption and potentially lasting for more than 30 minutes.[4][5][6][7] Decaffeinated coffee is also capable of generating a similar effect, albeit slightly weaker.[8] Essentially, this means for some people, coffee has a rapid-acting laxative effect.[9][10]

Clinical significance

Clinically, the gastrocolic reflex has been implicated in pathogenesis of irritable bowel syndrome (IBS): the very act of eating or drinking can provoke an overreaction of the gastrocolic response in some patients with IBS due to their heightened visceral sensitivity, and this can lead to abdominal pain and distension, flatulence, and diarrhea.[11][1] The gastrocolic reflex has also been implicated in pathogenesis of functional constipation, where patients with spinal cord injury and diabetics with gastroparesis secondary to diabetic neuropathy have an increased colonic transit time.[1]

The gastrocolic reflex can also be used to optimise the treatment of constipation. Since the reflex is most active in the mornings and immediately after meals, consumption of stimulant laxatives, such as sennosides and bisacodyl, during these times will augment the reflex and help increase colonic contractions and therefore defecation.[1]

References

  1. ^ a b c d e f Malone, Jordan C.; Thavamani, Aravind (2019), "Physiology, Gastrocolic Reflex (Gastrocolic Response)", StatPearls, StatPearls Publishing, PMID 31751078, retrieved 2020-01-14
  2. ^ Lauralee, Sherwood (2009). Human Physiology: From Cells to Systems (7th ed.). Cengage Learning. p. 635. ISBN 978-0-495-39184-5.
  3. ^ Tobias, Abraham; Sadiq, Nazia M. (2019), "Physiology, Gastrointestinal Nervous Control", StatPearls, StatPearls Publishing, PMID 31424852, retrieved 2020-01-14
  4. ^ Brown, Steven R.; Cann, P. A.; Read, Nicholas W. (1990). "Effect of coffee on distal colon function". Gut. 31 (4): 450–453. doi:10.1136/gut.31.4.450. PMC 1378422. PMID 2338272.
  5. ^ Eamudomkarn, Nuntasiri; Kietpeerakool, Chumnan; Kaewrudee, Srinaree; Jampathong, Nampet; Ngamjarus, Chetta; Lumbiganon, Pisake (2018). "Effect of postoperative coffee consumption on gastrointestinal function after abdominal surgery: A systematic review and meta-analysis of randomized controlled trials". Scientific Reports. 8 (1). 17349. Bibcode:2018NatSR...817349E. doi:10.1038/s41598-018-35752-2. PMC 6255780. PMID 30478433.
  6. ^ Sloots, Cornelius E.J.; Felt-Bersma, Richelle J.F.; West, Rachel L.; Kuipers, Ernst J. (2005). "Stimulation of defecation: Effects of coffee use and nicotine on rectal tone and visceral sensitivity". Scandinavian Journal of Gastroenterology. 40 (7): 808–813. doi:10.1080/00365520510015872. PMID 16109656. S2CID 23622961.
  7. ^ Dulskas, Audrius; Klimovskij, Michail; Vitkauskiene, Marija; Samalavicius, Narimantas (2015). "Effect of Coffee on the Length of Postoperative Ileus After Elective Laparoscopic Left-Sided Colectomy". Diseases of the Colon & Rectum. 58 (11): 1064–1069. doi:10.1097/DCR.0000000000000449. PMID 26445179. S2CID 45213244.
  8. ^ Nehlig, Astrid (2022). "Effects of Coffee on the Gastro-Intestinal Tract: A Narrative Review and Literature Update". Nutrients. 14 (2): 399. doi:10.3390/nu14020399. PMC 8778943. PMID 35057580.
  9. ^ Francis, Ali (2023-08-18). "Why Does Coffee Make You Poop?". Bon Appétit. Archived from the original on 2023-08-20. Retrieved 2023-10-27.
  10. ^ "Why Coffee Makes You Poop". Cleveland Clinic. January 24, 2023.
  11. ^ Sjölund K, Ekman R, Lindgren S, Rehfeld J (1996): Disturbed motilin and cholecystokinin release in the irritable bowel syndrome in Scand J Gastroenterol, 31:11, pp 1110–4, PMID 8938905, DOI 10.3109/00365529609036895