Constipation

In my office the topic of bowel movements is quite common. Probably more common than the discussion of the weather. Fine with me...really. I welcome the discussion as I personally find it important to deshame discussions like this and get it out in the open...literally and physically.


Saying “I feel constipated” may be different then saying “ I am constipated.”


These are all ways constipation may be experienced by you.


Here are some ways to describe it:


“ I have difficulty making a bowel movement”

“ I have discomfort when I make a bowel movement’

“ I have to strain to make a bowel movement”

“ I have hard stool"

“ I can go days without making a bowel movement’


So what is exactly qualifies as constipation?


The Rome III criteria revised in 2006 for functional constipation is as follows:


. Two or more of the following must be present

  • Straining must be present in at least 25% of defecations

  • Lumpy or hard stools in at least 25% of defecations

  • Sensation of incomplete evacuation for at least 25% of defecations

  • Sensation of anorectal obstruction/blockage for at least 25% of defecations

  • Manual maneuvers to facilitate at least 25% of defecations

  • Fewer than three defecations per week.

Chronic functional constipation is when one meets this criteria for greater than three months.


What places one at risk for constipation?

  • Being an elder

  • Female gender

  • Low level of education

  • Low level of physical activity

  • Non-white ethnicity

  • Low economic status


What does being female have to do with it and why is it better at some times of the months then others?


Constipation is thought to be 2-3 times higher in women than men. Colonic transit time is significantly longer in women during the luteal phase of menstrual cycle compared with the follicular phase, when estrogen levels are low.


Overexpression of progesterone receptors on colonic smooth muscle cells has been reported to downregulate contractile G proteins and upregulate inhibitory proteins.


G-proteins are a common receptor on a target organ that allows for hormone binding. So if the hormone progesterone is in a high state compared to estrogen states then receptors may be down regulating that would normally promote contraction in the colon. Around day 14-16 of the cycle estrogen begins to fall and progesterone climbs. Of note, In eating disorders we see a chronically low estrogen state.


Overexpression of progesterone receptors in colon epithelial cells is also associated with reduced serotonin transporter, high 5-hydroxytryptamine and normal tryptophan hydroxylase levels. (Hall, 2011)


5-hydroxytryptamine (5-HT) is a mediator associated with inflammation. 5-HT resides in the enteroendocrine cells of the intestine and is released following stroking of the intestinal lining or with increased pressure , such as after a meal.


5-HT then acts on a primary intrinsic afferent neuron to initiate the peristalsis reflex via ascending excitation and descending inhibition.


There is some thinking in the literature that increased 5-HT leads to sensitization of the receptors leading to constipation. Almost like the receptors are oversaturated and the normal action of 5-HT is not as functional. This is not confirmed. (Ford & Talley, 2015).


We do know serotonin regulation plays a critical role in intestinal motility, sensation, and secretion.


Over-secretion of serotonin such as in carcinoid tumors leads to the diarrhea seen in this disorder. Drug companies have tried to manipulate the serotonin pathways by trying to block 5-HT in diarrhea with drugs like alosetron(Zofran) and have tried to push or have agonistic effects on 5-HTP for constipation with drugs like tegaserod (a weak 5-HTP agonist).


In addition, overexpression of progesterone receptor B on colonic muscle cells, thereby making them more sensitive to physiologic concentrations of progesterone, has been proposed as an explanation for severe slow-transit constipation in some women. (Lembo, 2015)


One of the most consistent things I see in practice is the prevalence of people on constipating medications. We need to be aware of this as an underlying cause and be aware of the types of medications that cause constipation such as:

  • Acetaminophen >7 tablets weekly

  • Antacids that contain aluminum

  • Anticholinergic drugs: (ie. Anti-parkinsonian drugs, antipsychotics, antispasmodic, tricyclic antidepressants.

  • Anticonvulsants (Carbamazepine, phenobarbital, phenytoin

  • Calcium Channel Blockers (verapamil)

  • Calcium Supplements

  • Diuretics (ie. Furosemide)

  • 5-hydroxytryptamine antagonist (alosetron)

  • Iron supplements

  • NSAIDS (ibuprofen)

  • MU-opioid agonist (ie. Fentanyl, loperamide, morphine)


Some Things to think about if you are constipated.

Posture during bowel opening


The human body's natural posture for bowel opening is to squat. The nearest approximation is the 'brace and bulge' technique shown below:



Whilst sitting on the toilet, the knees are raised so they are higher than the hips (you can be use a footstool, or something similar to help); back is straight; lean forward, resting your elbows on knees, if possible; movement of stools can then be helped by bracing the abdominal muscles and bulging the abdominal wall outwards.


Knees higher than hips


Lean forward


Put elbows on knees


Bulge abdomen


Straighten spine