Roger, they use the word spasm because its more laymans termonology, both for some physicians and patients."Thanks, but I don't believe normal peristalsis feels like anything at all."It doesn't unless you have IBS and sensitive nerves, or viceral hypersensitvity. The brain is involved in that aspect.There are abnormal sensations to normal gut contractions for one.The gut can also contract anywhere along it length in IBS, as oppose to normal contractions that move food out.Antispasmatics actually work on contractions.altered colon contractions can cause different stool shapes.Irritable Bowel Syndrome (IBS): Examining New Findings and TreatmentsAuthors: Marvin M. Schuster, MD; Michael D. Crowell, PhD; Nicholas J. Talley, MD, PhD"Physiological Differences in IBS Patient SubgroupsThe gastrocolic reflex, a partly neurogenic process, refers to an increase in colonic motility induced by feeding. Postprandial deviations from the normal motility patterns lead to altered bowel habits. For example, a spastic colon (eg, diarrhea-predominant IBS [D-IBS]) is characterized by an exaggerated motility response to food intake. This exaggerated postprandial response also occurs in response to intraluminal distention or to an injection of cholecystokinin (CCK -- a hormone released in the duodenum) in patients with IBS."Graph normal humanGraph IBS " Effects of Balloon Distention on Rectosigmoid MotilitySmooth muscles in the colon can impede and/or facilitate the movement of intraluminal contents. Haustral contractions impede stool movement; high-amplitude propagating contractions (HAPCs) are sweeping propulsive motor events that are typically clustered around bowel movements. The frequency of HAPCs is increased in D-IBS. In contrast, HAPCs are fewer and segmental impeding contractions are more frequent in constipation-predominant IBS (C-IBS). In summary, C-IBS is characterized by postprandial rectal relaxation, blunted gastrocolic response, and lower rectal discomfort threshold. On the other hand, D-IBS is characterized by a postprandial increase in rectal tone, an enhanced gastrocolic response, and hypersensitivity to rectal distention."
http://www.medscape.com/viewprogram/725_pnt FYIGut 1999;45(Suppl 2):II17-II24 ( September )Principles of applied neurogastroenterology: physiology/motility-sensationJ E Kellowa, M Delvauxb, F Azpirozc, M Camillerid, E M M Quigleye, D G Thompsonf"Many of the symptoms characteristic of the functional gastrointestinal disorders (FGID) are consistent with dysfunction of the motor and/or sensory apparatus of the digestive tract. Those aspects of sensorimotor dysfunction most relevant to the FGID include alterations in: gut contractile activity; myoelectrical activity; tone and compliance; and transit, as well as an enhanced sensitivity to distension, in each region of the gastrointestinal tract.""Introduction Motility of the digestive tract encompasses the phenomena of myoelectrical activity, contractile activity, tone, compliance, and transit. In the functional gastrointestinal disorders (FGID), various types of dysmotility have been documented repeatedly, and most likely reflect dysfunction at one or more levels of the brain-gut axis. Patients with FGID also exhibit sensory afferent dysfunction, manifest as an altered sensitivity to stimuli such as distension of the gut, and selectively affecting the visceral territory. "Digestive tract sensorimotor physiology and pathophysiologyBASIC CONCEPTS AND DEFINITIONS RELEVANT TO THE FGIDMotilityContractile activity and tone
http://gut.bmjjournals.com/cgi/content/full/45/suppl_2/II17 Spasms are probably used for the layman. Its easier to explain then the above information and link.spasms, contractions (and there are different kinds), alter motility, distension etc. etc..This however I believe is an important topic in how the bowel works in general and in IBS and when distended, pressure sensitve cells release neurotransmitters to intiate contractions and communicate with the brain."CauseIBS is not caused by structural, biochemical, or infectious abnormalities. Rather,
IBS is considered a dysregulation, or abnormality of brain-bowel function. There is increased pain sensitivity and abnormal motility (increased or irregular muscular movement of the gut). In IBS, diarrhea comes from an increased rate of passage of stool through the colon. Constipation is the result of a decreased speed of stool passing through the colon. Spasms, which are very strong contractions, also occur in IBS. Increased pain sensitivity results from the increased sensitivity of the nerves. Sometimes, the nerves are so sensitive that normal contractions, even with digesting a normal meal, bring on pain or discomfort."
http://www.med.unc.edu/medicine/fgidc/question.htm I would say something important here in IBS is "the nerves are so sensitive that normal contractions, even with digesting a normal meal, bring on pain or discomfort.""So they use the word spasms as very strong contractions in the gut.I also emailed the experts on this at UNC."I was actually curious about all this myself, so I talked to an expert today about it.Technically and more accurately they are not spasms, but contractions.Even though a more archaic name for IBS use to be spastic colon. The word spasms might still be used more for laymans and for simplicities sake."