Laxative bulk-forming

Obstruction of the esophagus, stomach, small intestine, and colon has occurred when bulk-forming laxatives are administered without adequate fluid intake or in patients with intestinal stenosis. 

For some bedridden or geriatric patients, or others with chronic constipation, bulk-forming laxatives remain the first line of treatment, but the use of more potent laxatives may be required relatively frequently. Agents that may be used in these situations include milk of magnesia and lactulose. 

Bisacodyl is a stimulant laxative that does not take long to act and is therefore useful in acute constipation. The bulk-forming laxative ispaghula husk takes longer to act when compared with bisacodyl but is useful for long-term administration. Lactulose, which is an osmotic laxative, has a lag time of about 48 hours before onset of action. Loperamide and kaolin and morphine mixture are antidiarrhoeals used in acute diarrhoea. 

Bulk-forming laxatives may interfere with drug absorption. 

Constipation bulk-forming laxatives by increasing faecal mass tend to soften stools and relieve constipation, and have value in a range of symptomatic problems associated with anal fissure, haemorrhoids, and with ileostomy and colostomy dysfunction. Faecal softeners, lactulose and macrogols (polyethylene glycol) retain fluid in the bowel. Stimulant laxatives, such as the anthraquinone, senna, and bisacodyl, increase motility and can cause colic verdoses can cause diarrhea and electrolyte depletion. Chronic treatment for constipation is seldom needed, but may be in children with a tendency to faecal impaction, specialist advice should be sought. 

The bulk-forming laxative group includes the hydrophilic substances described previously calcium polycarbophil FiberCon, Equalactin), methylcellulose Citrucel), and various psyllium seed derivatives Metamucil). All act by increasing the bulk of the feces, part of this action being due to their capacity to attract water and form a hydrogel. The increased volume of feces stretches the walls of the GI tract and stimulates peristalsis. Their action may not be evident for 2 to 3 days after starting treatment. Because their use results... 

Since clear advantages accrue from a high-bran diet (a reduction in both constipation and diverticulitis) and since there is no associated toxicity, a bulk-forming laxative is the laxative of choice for constipated patients. 

PO044 Etman, M. A. Effect of a bulk forming laxative on the bioavailability of car-bamazepine in man. Drug Dev Ind Pharm 1995 21(16) 1901-190. 

Mechanism of Action A bulk-forming laxative that dissolves and expands in water. Therapeutic Effect Provides increased bulk and moisture content in stool, increasing peristalsis and bowel motility. 

Bulk-forming laxatives are indigestible, hydrophilic colloids that absorb water, forming a bulky, emollient gel that distends the colon and promotes peristalsis. Common preparations include natural plant products (psyllium, methylcellulose) and synthetic fibers (polycarbophil). Bacterial digestion of plant fibers within the colon may lead to increased bloating and flatus. 

Bulk-forming laxatives Methylcellulose, psyllium, etc increase volume of colon, stimulate evacuation... 

Bulk-Forming Laxatives. These agents absorb water and swell within the lower GI tract. The increased size of the water-laden laxative stretches the bowel, thus stimulating intestinal movement (peristalsis). Bulk laxatives commonly contain natural and semisynthetic dietary fiber such as bran, psyllium, and methylcellulose. 

E. Metamucil, a bulk forming laxative, is leading to dehydration, which gives rise to fatigue and cramps. 

Bulk-forming laxatives (such as ispaghula husk), which work by increasing faecal mass, but they may take several days to become fully effective. They are of most use in those patients that pass small stools and have a diet lacking in fibre (but they should not replace dietary lifestyle measures)... 

Bulk-forming laxatives - increase the volume of the stool to stimulate peristalsis. 

Certain bulk-forming laxatives, such as ispaghula husk and psyllium, can impair the absorption of lithium (654). 

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