++
It is important to ask patients to define exactly what they mean by constipation. Some people believe that just as the earth rotates on its axis once a day, so should their bowels open daily to ensure good health. As always, a careful history is appropriate, including stool consistency, frequency, ease of evacuation, pain on defecation and the presence of blood or mucus. A dietary history is very relevant in the context of constipation.
++
How often do you go to the toilet?
What are your bowel motions like?
Are they bulky, hard, like rabbit pellets or soft?
Is there pain on opening your bowels?
Have you noticed any blood?
Have you noticed any lumps?
Do you have any soiling on your underwear?
How do you feel in yourself?
What medications are you taking?
++
Ask the patient to keep a 10-day diary recording frequency and nature of stools, and whether any difficulty was experienced when passing stool.
++
The important aspects are abdominal palpation and rectal examination. Palpation may reveal the craggy mass of a neoplasm, faecal retention (especially in the thin patient) or a tender spastic colon. The perianal region should be examined for localised disease. The patient should be asked to bear down to demonstrate perianal descent, haemorrhoids or mucosal prolapse. Perianal sensation and the anal reflex should be tested. Digital rectal examination is mandatory, and may reveal a rectal tumour and faecal impaction, as well as testing for rectal size and tone. If there is a history from infancy, a normal or narrow rectum suggests congenital megacolon (Hirschsprung disorder) but, if dilated, acquired megacolon.
++
General signs that may be significant in the diagnosis of constipation are summarised in FIGURE 41.2.
++
++
The most important first step is to do the examination.
++
Explain to the patient what will happen.
After inspection with the patient in the left lateral position and with knees drawn up, a lubricated gloved index finger is placed over the anus.
Part the buttocks.
Ask the patient to concentrate on slow deep breathing.
With gentle backwards pressure the finger is then inserted slowly into the anal canal and then into the rectum (it helps patient comfort if they push down or squeeze to accommodate the finger).
Rotate the finger anteriorly to feel the prostate in males and the cervix in females.
The finger will reach to about 7–8 cm with gentle thrusting into the perineum.
Gently withdraw the finger and examine the whole circumference of the rectum by sweeping the finger from posterior on both sides.
++
Any pain: fissure, proctitis, excoriation from diarrhoea (a rectal examination will not be possible in the presence of a fissure)
Induration from a chronic fissure or fistula in the anal canal
The sphincter tone
The nature of the faeces (? impaction)
The rectal wall: cancer is usually indurated, elevated and ulcerated; a villous adenoma has a soft velvety feel
Posteriorly: the sacrum and coccyx
Laterally: the side walls of the pelvis
Anteriorly: cervix and pouch of Douglas in the female; prostate and rectovesical pouch in the male
++
It feels larger if the patient has a full bladder.
The normal prostate is a firm smooth rubbery bilobed structure (with a central sulcus) about 3 cm in diameter.
A craggy hard mass suggests cancer.
An enlarged smooth mass suggests benign hypertrophy.
A tender, nodular or boggy mass suggests prostatitis.
++
Practice tip on treatment
A suitable method of doing a rectal examination on a home visit (in the absence of gloves in the doctor’s bag) is to apply moist soap around the finger and caked under the nail (in case of breakage), then plastic wrap and finally petroleum jelly (e.g. Vaseline).
Before resorting to a good old-fashioned ‘3H’ enema (hot water, high and a hell of a lot), use a sorbitol compound (e.g. Microlax 5 mL enema). It can be carried in the doctor’s bag, is very easy to insert and is most effective.
++
In the female, the cervix or a vaginal tampon can be mistaken for a mobile extrarectal tumour.
++
Sigmoidoscopy—in particular, flexible sigmoidoscopy with examination of the rectosigmoid—is important in excluding local disease; search for abnormalities such as blood, mucus or neoplasia. The insufflation of air sometimes reproduces the pain of the irritable bowel syndrome.
++
It is worth noting that 60% of polyps and cancers will occur in the first 60 cm of the bowel4 and diverticular disorder should be evident with the flexible sigmoidoscope.
++
The presence of melanosis coli is an important sign—it may give a pointer to the duration of the constipation and the consequent chronic intake (perhaps denied) of anthraquinone laxatives.
++
These can be summarised as follows:
++
+++
Idiopathic constipation
++
It is best to classify idiopathic constipation into three subgroups:
++
simple constipation
slow transit constipation
normal transit constipation (irritable bowel syndrome)
++
Of these, the commonest is simple constipation, which is essentially related to a faulty diet and bad habit. Avery Jones,7 who defined the disorder, describes it as being due to one or more of the following causes:
++
faulty diet—inadequate dietary fibre
neglect of the call to stool
unfavourable living and working conditions
lack of exercise
travel
++
Dyschezia, or lazy bowel, is the term used to describe a rectum that has become unresponsive to faecal content, and this usually follows repeated ignoring of calls to defecate.
++
Slow transit constipation occurs primarily in women with an apparently normal colon, despite a high-fibre intake and lack of the other causes described by Avery Jones. Many are young, with a history dating from early childhood or, more commonly, adolescence. Constipation may follow childbirth, uncomplicated abdominal surgery or a period of severe dieting. However, in the majority no precipitating cause is evident.
++
A defecatory disorder is where there is a paradoxical contraction rather than normal relaxation of the anal sphincter and associated muscles responsible for evacuation. Also known as dyssynergic dysfunction.
++
Most patients have simple constipation and require reassurance and education once an organic cause has been excluded. Encourage modification of lifestyle.
++
Adequate exercise, especially walking, is important.
Develop good habit: answer the call to defecate as soon as possible. Develop the ‘after breakfast habit’. Allow time for a good relaxed breakfast and then sit on the toilet. Don’t miss meals—food stimulates motility.
Avoid laxatives and codeine compounds (tablets or mixture).
Take plenty of fluids, especially water and fruit juices (e.g. prune juice).
Eat an optimal bulk diet. Eat foods that provide bulk and roughage, such as vegetables and salads, cereals (especially wheat fibre), fresh and dried fruits, and wholemeal bread. Enough fibre should be taken to convert stools that sink to stools that float.
++
Examples of food with good bulk properties are presented in TABLE 41.3.8 Fruit has good fibre, especially in the skin, and some have natural laxatives (e.g. prunes, figs, rhubarb, apricots).
++
+++
Treatment (pharmaceutical preparations)
++
Some patients may not tolerate unprocessed bran but tolerate pharmaceutical preparations better (see TABLE 41.4). An appropriate choice would be one of the hydrophilic bulk-forming agents such as ispaghula or psyllium. Avoid stimulant laxatives except for short sharp treatments.
++
++
Use a general bulking agent e.g. psyllium or ispaghula granules 1–2 teaspoonsful (o) once or twice daily, or Benefiber® 2 teaspoonsful (o) twice daily.
++
Use an osmotic laxative or a fibre-based stimulant preparation e.g. macrogol 3350 + 1–2 sachets, each dissolved in 125 mL water once daily
or
lactulose syrup, 15–30 mL (o) daily until response, then 10–20 mL daily
or
dried fruits with senna leaf (Nu-Lax) 10 g nocte
or
docusate + senna (50–80 mg), 1–2 tabs nocte
++
++
Magnesium sulphate 1–2 teaspoons (15 g) in water once or twice daily (if normal kidney function)
or
as capsules (Colocap Balance) 15 caps over 15 minutes
or
combined bulking/stimulating agent (e.g. frangula/sterculia [Normacol plus])
or
glycerin suppository (retain for 15–20 minutes)
or
sodium citrate or phosphate enema (e.g. Fleet Enema)
or
Microlax enema
+++
Constipation in children
++
Constipation is quite common in children but no cause has been discovered in up to 95%. The most common factor is diet. Constipation often begins after weaning or with the introduction of cow’s milk. It is rare with breastfeeding. Low fibre intake and a family history of constipation may be associated factors.5 Most children develop normal bowel control by 4 years of age (excluding any physical abnormality). It is normal to have a bowel movement every 2–3 days, providing it is of normal consistency and is not painful.
++
It is important to differentiate between encopresis and constipation:
++
Constipation usually appears between 2 and 4 years of age, and up to a third of primary school-aged children will report constipation over a 12-month period. In toddlers, the gender distribution is equal, but by age 5, boys are more likely to get constipation than girls, with the frequency of faecal incontinence three times higher in boys.
++
Constipation in children is defined as having two or more of the following over the previous 2 months:
++
<3 bowel motions per week
>1 episode of faecal incontinence per week (previously referred to as encopresis)
large stools in rectum or palpable on abdominal examination
retentive posturing (e.g. ‘stiff as a board’ standing/lying, tip toes, crossed legs, braces against furniture) and withholding behaviour (e.g. refuses, hides, requests nappy, denies need to go)
painful defecation
++
Faecal incontinence, which is a consequence of chronic constipation, is the passage of stool in an inappropriate place in children who have been toilet trained. It can present as soiling, due to faecal retention with overflow of liquid faeces (spurious diarrhoea) aka encopresis.
++
Constipation is nearly always functional (>95%),6 though the GP should check for any red flags for a pathological cause (see below). The key feature in functional constipation is chronic faecal retention leading to rectal dilatation and insensitivity to the normal defecation reflex.
++
Red flag pointers for organic causes
Blood in stools
Perianal disease
Fever
Weight loss/delayed growth
Delayed meconium/thin strip-like stools
Vomiting
Urinary symptoms
Abnormal neurological findings in legs
Medications used for children with behavioural/developmental issues
++
Normally the rectum is empty just prior to defecation; with faecal retention, the rectum is stretched, weak and numb and it can leak.
+++
Other important conditions
++
++
++
++
+++
Principles of treatment of functional constipation5,6
++
Encourage relaxed child–parent interaction with toilet training, such as appropriate encouragement, ‘after breakfast habit’ training, regular toileting (where possible), three times/day for 3–5 minutes, reinforce desired behaviour with stickers on an age-appropriate chart.
Introduce psychotherapy or behaviour modification program, especially where ‘fear of the toilet’ exists.
Establish an empty bowel: remove any severely impacted faeces with microenemas (e.g. Microlax), and even disimpaction under anaesthesia if necessary. A good guide if faecal ‘rocks’ are visible on X-ray.
Advice for parents of children over 18 months:
– Drink ample non-milk fluids each day—several glasses of water, unsweetened fruit juice (be cautious of cow’s milk).
– Use prune juice, which contains sorbitol.
– Get regular exercise—walking, running, outside games or sport.
– Provide high-fibre foods—high-fibre cereals, wholegrain bread, brown rice, wholemeal pasta, fresh fruit with skins left on where possible, dried fruits such as sultanas, apricots or prunes, fresh vegetables.
Advice on correct posture and position—‘how to do a poo’:5
– Feet supported (e.g. with a foot stool)
– Knees higher than bottom and apart
– Leaning forward with elbows on knees
– Encourage child to push out stomach
– Ensure privacy (including at preschool/school)
Laxatives—if constipation has been brief in duration, treat for 3 months, but for chronic constipation, treat for 6 months minimum.
Can use macrogol 3350 (Movicol), paraffin oil or lactulose.
For acute faecal impaction, high-dose laxatives can be used until liquid stools are achieved, and then revert back to maintenance treatment. Enemas are suitable only for children with acute severe rectal pain or distress and are rarely required.
Use a pharmaceutical preparation as a last resort to achieve regularity.
++
++
++
Severe constipation/faecal impaction:
++
++
If unsuccessful, add ColonLYTELY via nasogastric tube or sodium phosphate enema (Fleet Enema) (not <2 years).
+++
Constipation in the elderly
++
Constipation is a common problem in the elderly, with a tendency for idiopathic constipation to increase with age. In addition, the chances of organic disease increase with age, especially colorectal cancer, so this problem requires attention in the older patient. Faecal impaction is a special problem in the aged confined largely to bed. Constipation is often associated with Parkinson disease. In the elderly, an osmotic laxative such as sorbitol or lactulose may be required for long-standing refractory constipation, but stimulant and other non-osmotic laxatives should be avoided.
++
This is a difficult problem, especially in the older person who may not be aware of the problem especially if they have spurious diarrhoea. Symptoms include malaise, anorexia and nausea, confusion, headache, abdominal discomfort ± colic and bloating, a sense of inadequate defecation and frequent amounts of small stool. Complications include spurious diarrhoea, faecal incontinence, bowel obstruction, urinary incontinence or retention. It often follows opioid medication. Confirm with rectal examination ± plain X-ray of abdomen. Treat with oral or osmotic laxatives (e.g. 8 sachets of macrogol 3350 for 3 days with or without rectal suppositories) or enema, e.g. Fleet Enema, Microlax.
++
If manual disimpaction should be necessary, the unpleasant procedure can be rendered virtually odourless if the products are ‘milked’ or scooped directly into a container of water. A large plastic cover helps restrict the permeation of the smell.
++
Discomfort and embarrassment are reduced by this method and by adequate premedication (e.g. IV midazolam and IV fentanyl) if large faecaliths are present.
++
Commonest GIT malignancy
Second most common cause of death from cancer in Western society
Generally men over 50 years (90% of all cases)
Mortality rate about 60%
Good prognosis if diagnosed early
Two-thirds in descending colon and rectum
++
Refer to section on genetics of colorectal cancer (see CHAPTER 18).
++
Ulcerative colitis (long-standing)
Familial: familial adenomatous polyposis (FAP), hereditary non-polyposis colorectal cancer
Colonic adenomata
Decreased dietary fibre
Age >50 years
++
This is determined by the family history (see TABLE 41.5).
++
++
Consider referral to a familial cancer clinic for assessment.
++
Blood in the stools
Mucus discharge
Recent change in bowel habits (constipation more common than diarrhoea)
Alternating constipation with spurious diarrhoea
Bowel leakage when flatus passed
Unsatisfactory defecation (the mass is interpreted as faeces)
Abdominal pain (colicky) or discomfort (if obstructing)
Rectal discomfort
Symptoms of anaemia
Rectal examination—this is appropriate because many cancers are found in the lowest 12 cm and most can be reached by the examining finger
+++
Obstruction (distension with ↑ pain)
++
If obstructing, there is a risk of rupture of the caecum.
++
Surgery is needed to circumvent the closed loop obstruction.
++
++
Various forms of presentation of large bowel cancers are shown in FIGURE 41.3.
++
++
FOBT: immunochemical tests (e.g. Inform and InSure) do not require dietary or medication restriction
CT colonography (investigation of choice)
Serum CEA level is not useful for diagnosis but is useful for monitoring response to treatment
Sigmoidoscopy, especially flexible sigmoidoscopy
Double contrast, barium enema may miss tumours and is being superseded by other imaging
Ultrasonography and CT scanning not useful in primary diagnosis; valuable in detecting spread especially hepatic metastases
PET scanning (if available) is useful for follow-up
++
If FOBT is positive—investigate by colonoscopy or by flexible sigmoidoscopy.
++
An FOBT every 2 years is now recommended for all people from 50 years (see guidelines in CHAPTER 9).
++
Colonoscopy is recommended as follows:
++
Moderate risk: every five years from 50 years or 10 years younger than when a family member presented
High risk: guided by clinical genetics team but as a rule yearly or 2 yearly commencing at 25 years, and every 12 months from 12–15 years of age if a strong family history of FAP.11
++
In addition, flexible sigmoidoscopy and rectal biopsy for those with ulcerative colitis. Refer to a bowel cancer specialist to plan appropriate surveillance.
++
Early surgical excision is the treatment, with the method depending on the site and extent of the cancer. Dukes’ classification gives a guide to prognosis (see TABLE 41.6). The survival rates for Dukes C cancer have improved with more effective chemotherapy.
++
++
There are other classifications for staging of colorectal cancer, including the 0, I, II, III, IV and TNM systems.
++
++
+++
Congenital megacolon Hirschsprung disorder (aganglionosis)
++
Congenital
Constipation from infancy
Abdominal distension from infancy
Possible anorexia and vomiting
Male to female ratio = 8:1
Rectal examination—narrow or normal rectum
Abdominal X-ray/barium enema—distended colon full of faeces to narrow rectum
Diagnosis, confirmed by full thickness biopsy, shows absence of ganglion cells
Absent rectoanal reflex on anal manometry
++
Resect narrow segment after preliminary colostomy.
++
In older children and adults
Mainly due to bad habit
Can be caused by:
– chronic laxative abuse
– milder form of Hirschsprung disorder
– Chagas disease (Latin America)2
– hypothyroidism (cretinism)
– systemic sclerosis
Marked abdominal distension
Rectal examination—dilate loaded rectum, lax sphincter
Abdominal X-ray/barium enema—distended colon full of faeces but no narrowed segment
++
Re-education of bowel habit is required.