- Constipation patients can be given ‘lessons’ on how to poo. At first many patients are wary of this technique and sceptical. It may take several lessons before they relax and settle down and understand what it is for, but it is possible to ‘learn’ how to poo normally again.
What causes constipation
- Lack of fibre & fluid intake
- Lack of physical activity
- Irritable bowel syndrome
- Drugs – particularly opiates, but also iron supplements, anti cholinergics, calcium antagonists and aluminium containing ant-acids.
- Neurological causes – e.g. MS, parkinson’s, a CVA, spinal chord lesions
- Metabolic causes – pregnancy, diabetes, hypercalcaemia, hypothyroidism
- Depression – possibly linked to general decreased activity of the nervous system and less 5-HT.
- Hirschprung’s disease
- Colonic carcinoma
- Diverticular disease
- Pregnancy – it has been shown that progesterone reduces colonic muscle tone, thus leading to constipation. This also sometimes has an effect during a woman’s menstrual cycle – if a woman is constipated, the symptoms may be worse during the luteal phase of her cycle.
- Diabetes, hyperthyroisim and hypercalcaemia can all lead to altered motility.
Types on constipation
- Normal transit constipation (59%) – in this type of constipation, stools travel through the colon at the normal rate. Patients also have normal stool frequency, but they believe they are constipated – this is probably because they have difficulty with the act of actually passing a stool. Patients often claim abdominal pain and bloating.
- This condition can be assessed by ingestion of radio markers – various shapes that are ingested on different days to identify how long it takes a shape to travel through the colon. This type of test helps distinguish slow transit from normal transit constipation
- Slow transit constipation (13%) – this often occurs in young women, and will result in defecation of less than once a week. The condition often starts at puberty and symptoms involves abdominal pain, bloating, and infrequent urge to defecate. The diagnosis can be difficult as it is similar to that of constipation due to IBS. Some patients with this condition have impaired bowel emptying, and some have impaired stimulation of colonic motility. Some patents will also have co-existing disorders of the small intestine that may be consistent with a diagnosis of chronic idiopathic pseudo-obstruction.
- Defacatory disorders (25%)- this is often caused by improper relaxation of the puborectalis muscle, external anal sphincter and other associated muscles of defecation. It is a bit of a paradox, because through straining too hard, people can prevent these muscles from relaxing. It is especially common in women and may actually be a learned response. Often an anterior rectocele may form. This is where there is a weakness in the rectal/vaginal septum, and a protuberance of the rectum may form If this protuberance has a diameter of >3cm, then faeces can get stuck in it. In other patients, the mucosa of the anterior wall of the rectum prolapses downwards during straining, preventing proper emptying of the rectum. In some patients, the rectum may become overly sensitive to the presence of small volumes of faces in the rectum, and as a result the patient will pass small volume stools frequently, and often have a sensation of incomplete evacuation.
- Defecation disorders can be diagnosed by using imaging of the rectum during defecation.
- You may want to perform a vaginal and rectal examination if you suspect that the constipation is caused by a pelvic floor defect (can happen in childbirth, trauma or in serious colonic disease). An easy way to rule this out is to see if the perineum descends on straining. If it does not, then it is a pelvic floor dysfunction.
- Radio opaque markers (as seen above)
- Check the perineum and do a PR. You might find impaired sensation or disorders of the rectal floor. You may also feel a rectal mass, or a prolapse, and it is very important when you do a PR that you ask the patient to squeeze your finger to test anal sphincter function.
- Normal and slow transit constipation – the first line treatment of this should be an increase of fibre and fluid intake in the diet. You should try to increase fibre through dietary means rather than with fibre supplements – as the supplements can affect the way floral bacteria operate thus not producing the desired effect. Patients should be encouraged to drink 6-8 glasses of water daily, and to eat 20-30g of fibre every day. This approach does not help in all cases.
- Laxatives –use of these should be restricted to very severe cases. There are different types that act in different ways
- Osmotic laxatives –these draw fluid out of the interstitia and into the colonic lumen. A common example is magnesium sulphate (5-10g), taken usually at breakfast time, it will work within 2-4 hours.
- Stimulatory laxatives –these work by stimulating the colonic mucosa to contract more often, thus, churning up the stool and moving it along the bowel quicker. Some may also increase intestinal secretion.
- Enema –this may be performed in the elderly and infirm, and those with neurological disorders.
For more information, see the article Altered Bowel Habit