Running diagnostics

Running diagnostics

Tuesday, September 4, 2018

Constipation

Today we are going to discuss a very common condition that I’m sure most of us have experienced at one point in our lives; so it’s going to be a topic that is very relatable. And it’s about POO! So it will relatable and awkward as well! Without further ado, let’s dive into the enemy of mankind and what many people view as the bane of their existence: constipation!

As always today's post is available in podcast form. Download it from www.medonthego.podbean.com or look for "Med On The Go" on iTunes and Google Play. Subscribe so you'll never miss an episode! Other useful/fun articles are available on our Facebook page www.facebook.com/drolimedonthego. If you wish to support our work, please visit www.patron.podbean.com/medonthego for more details. Thanks!

And on to today's topic:

Constipation is the passage of infrequent or hard stools with straining. “Infrequent” is defined as < 3 times/week, and “hard” is defined as stools with water content < 50ml. As mentioned previously, it is a very common condition, increasing in prevalence with age and affecting more females than males. Having said that, constipation is less common in Africa and India, where stool weight is 3~4 times greater than Western countries.

Constipation can have many different causes. The most common one is idiopathic, attributed to colon dysmotility—but this is very difficult to quantify. Other organic causes include medication side effects (narcotics, antidepressants), intestinal obstruction, left sided colon cancer (consider in older populations), and fecal impaction. Metabolic causes such as diabetes mellitus, hypothyroidism, hypercalcemia, hypokalemia, and uremia can also result in constipation, as do neurological causes such as intestinal pseudo-obstruction, Parkinson’s disease, and multiple sclerosis. Some collagen vascular diseases (e.g. scleroderma) can cause constipation; and painful anal conditions (e.g. fissures) can definitely cause constipation too.

Mnemonic for causes of constipation: DOPED
Drugs
Obstruction
Pain
Endocrine dysfunction
Depression

Clinical presentation of constipation can be very similar to that of IBS. The stool is firm, difficult to expel, and passed with straining. There is associated abdominal pain that is relieved by flatulence and defecation. Other symptoms include tenesmus, abdominal distention, overflow diarrhea, and infrequent bowel movements.

If constipation is the only symptoms, the underlying disease can be very difficult to find; the only test recommended by American Gastroenterology Association (2013) would be CBC—to exclude any sinister, systemic conditions. However, TSH, calcium, and glucose levels can also be helpful, as is an abdominal X-ray. If the constipation is associated with rectal bleeding, weight loss, or anemia, visualization of the colon through colonoscopy or CT colonography would be indicated.

For constipation that is refractory to treatment, colon transit time can be measured by having the patient ingest radio-opaque markers then taking a series of abdominal X-rays. The normal time is around 70 hours. If the colon transit time test result is indeed normal, then the patient has a misperception of normal defecation (IBS). If the result is prolonged throughout, the patient has “colonic inertia” (infrequent bowel movements with gas/bloating, often occurring in youth). If the result shows outlet obstruction, it could be that the patient is unable to coordinate pelvic muscles to empty rectum, causing straining. This tends to occur in old age, and often stool will be found in rectum on digital exam.

Treatment (in order of increasing potency):
·      Dietary fiber
o   Useful in mild/moderate constipation
o   Aim for 30g daily, increasing dosage slowly
·      Surface-acting agents (to soften and lubricate stools)
o   Docusate salts
o   Mineral oils
·      Osmotic agents (effective in 2~3 days)
o   Lactulose
o   Sorbitol
o   Magnesium salts
o   Lactitol
o   Polyethylene glycol 3350
·      Cathartics/stimulants (effective in 24 hours)
o   Castor oil
o   Senna (avoid prolonged use to prevent melanosis coli)
o   Bisacodyl
·      Enemas and suppositories
o   Saline
o   Phosphate
o   Glycerin
o   Bisacodyl
·      Prokinetic agents
o   Prucalopride

·      Linaclotide—increases water secretion into the intestinal lumen.

Upper GI Bleeds

As always, this blog post is available in podcast form at www.medonthego.podbean.com. You can also find Med On The Go on iTunes and Google ...