Constipation normal-transit

Constipation can be due to primary and secondary causes (Table 18-1). Primary or idiopathic constipation is typified by normal-transit constipation, slow-transit constipation, and dyssynergic defecation. In the normal-transit type, colonic motility is unchanged and patients tend to experience hard stools despite normal movements. In the slow-transit type, motility is decreased leading to infrequent harder, drier stools. In dyssynergic defecation (also known as pelvic floor dysfunction), patients have lost the ability to relax the anal sphincter while coordinating muscle contractions of the pelvic floor. Some causes of secondary constipation are listed in Table 18-1. 

Normal-transit constipation (includes idiopathic or functional disorders)... 

The first observation in this field was made by Heaton et al In normal-weight women with gallstones but no other obvious risk factors, the Bristol investigators found that, compared with age- and sex-matched controls, the gallstone carriers had almost a 20-h longer whole gut transit time. Despite this, their mean faecal wet weight was only half that of the controls. Put another way, the women with gallstones had slow transit constipation. 

Laxative effect. Seed hull, taken orally by adults at a dose of 7 g/person, increased weekly fecal mass without influencing transit time or frequency . Seedcoat, administered orally to 80 patients at a dose of 6.4 g/person three times daily, was active in a blinded placebo controlled study of efficacy of extract in treatment of irritable bowel syndrome " . Water extract of the dried kernel, administered orally to 40-year-old adults of both sexes, was active . Seed powder, administered orally to adults of both sexes, was active. Biological activity reported has been patented ". Dried seeds, administered orally to adults at a dose of 0.5 g/person, were active. Placing the seeds in water increased their volume, 90% alcohol produced a decrease in volume to normal seed size, and linseed oil had no effect on volume. The seed mucilage remained in gel form and is considered preferable to the solid form because it is more easily digested " . Dried seed powder, administered orally to 35 patients with chronic constipation at a dose of 50 mg/person, was active in a controlled, double-blind study " . Fiber, administered orally to adults, was active. Psyllium fiber and sennosides were prepared into a wafer to be... 

Under normal circumstances, these quantities are well within the range of the total absorptive capacity of the small bowel ( 16 L) and colon (4-5 L). Neurohumoral mechanisms, pathogens, and drugs can alter these processes, resulting in changes in either secretion or absorption of fluid by the intestinal epithelium. Altered motility also contributes to this process, as the extent of absorption parallels transit time. With decreased motility and excess fluid removal, feces can become inspissated and impacted, leading to constipation. When the capacity of the colon to absorb fluid is exceeded, diarrhea will occur. 

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