Lazy Bowels: Causes of Constipation and Treatment

There is no medical diagnosis of "lazy bowel syndrome." This is the common name for chronic constipation —a condition characterized by infrequent stools, straining, and a sensation of incomplete evacuation, sometimes due to slow transit through the colon ("colonic inertia"), sometimes due to impaired coordination of the pelvic floor muscles during defecation (dyssynergia), and often a combination of both. The Rome IV criteria for functional constipation and constipation associated with constipation-predominant irritable bowel syndrome (IBS-C) provide a valid diagnostic framework. [1]

Important: "lazy" bowel function does not mean a permanently damaged bowel. In most cases, these are reversible functional disorders that can be corrected through lifestyle changes, modern laxatives, pelvic floor muscle training (biofeedback), and, if necessary, prescription medications that affect secretion and motility. [2]

Another common context is constipation caused by medications, primarily opioids (opioid-induced constipation), as well as some antidepressants, calcium antagonists, iron antagonists, and anticholinergics. Here, the approach is different: in addition to the usual stage of therapy, peripheral μ-opioid receptor antagonists are often used. [3]

Finally, in some people, constipation is attributed to behavioral triggers (ignoring bowel movements, inactivity, low fiber/fluid intake) and is exacerbated by anxiety and "toilet anxiety." It's best to start with simple corrections, but don't delay an examination if you have any "warning signs" (see below). [4]

How to distinguish functional constipation from dangerous causes

Most people with a typical presentation do not require a specialized, in-depth diagnostic workup. However, it is important for a physician to be alert for any red flags: unexplained weight loss, blood in the stool, anemia, fever, nocturnal symptoms, constipation onset after age 50, familial colon cancer/polyposis, severe pain, and neurological impairment. If these are present, a colonoscopy and targeted testing are indicated. If no red flags are present, a physical examination, medication review, and a complete blood count are usually sufficient; routine hormone/calcium/sugar tests are not recommended without clinical justification. [5]

Colonoscopies are not performed without flags (except for routine age/risk-based screening). If laxatives are ineffective, the next step is anorectal manometry and a balloon expulsion test to rule out dyssynergia; visualization (defecography) is not necessary for everyone and is usually performed after functional tests. [6]

To differentiate slow transit from normal transit, marker capsules or a wireless motile capsule are used; this is useful in patients who have not responded to basic therapy. The results influence the choice of tactics (emphasis on prokinetics vs. biofeedback). [7]

A diagnosis of functional constipation according to Rome IV is made in the presence of ≥2 symptoms (straining, fragmented stools, sensation of incomplete evacuation/blockage, manual efforts, <3 bowel movements per week) for ≥3 months (with an onset ≥6 months ago), and the criteria for IBS-C are not met. [8]

Table 1. When and what to examine

Scenario	What to do	For what
No red flags, typical history	Examination, medication review, stool diary, start of therapy	It is safe to start treatment without unnecessary tests. [9]
Laxatives didn't help	Anorectal manometry + balloon expulsion	Exclude dyssynergia (otherwise the medications “will not work”). [10]
Suspected of slow transit	Transit test (markers/capsule)	Confirm "colonial inertia". [11]
Red Flags	Colonoscopy and targeted testing	Rule out organic factors (cancer, inflammation, etc.). [12]

Why constipation occurs: mechanisms in simple terms

Slow transit: wave-like contractions of the colon are infrequent and weak, water takes longer to be absorbed, and stools become hard and infrequent. This may be due to a congenital motility disorder, age-related changes, physical inactivity, or a lack of fiber/fluid. [13]

Pelvic floor dyssynergia: the sphincter and pelvic floor muscles, instead of relaxing during straining, paradoxically tense – a "door is locked" sensation. Symptoms include prolonged sitting on the toilet, a feeling of blockage, and the need for manual assistance. Laxatives are ineffective; training with biofeedback is needed. [14]

Drug-induced constipation: opioids inhibit peristalsis and secretion, anticholinergics reduce tone, iron/antacids make stool heavier, and some antidepressants slow motility. Solutions: replace/reduce the dose if possible; for opioid-induced constipation, use specialized medications (see treatment). [15]

Psycho-behavioral factors: suppression of urges (a rushed schedule, "no suitable toilet"), anxiety, low activity. These factors often "maintain" constipation even when the underlying cause is medical. The plan always includes a behavioral component. [16]

Treatment: A Modern Turn-Based Strategy

The 2023 AGA/ACG (USA) guidelines and large reviews converge on a stepwise approach: (1) lifestyle and over-the-counter agents → (2) prescription secretagogues/prokinetics → (3) targeted pelvic floor rehabilitation; surgery is reserved for carefully selected refractory cases with proven colonic inertia. [17]

Step 1: Lifestyle and Over-the-Counter Remedies

• Fiber (soluble - psyllium/oats; target 20-30 g/day) + adequate hydration, gentle physical activity. Helps a significant proportion of patients, but with slow transit, the effect is limited. [18]
• Osmotic laxatives: polyethylene glycol (PEG) is the first line; lactulose is an alternative. Well-studied and safe for long-term use. [19]
• Magnesium oxide is now also recommended as an option for adults (with caveats regarding kidney function). [20]
• Stimulant laxatives (bisacodyl, senna, sodium picosulfate) effectively stimulate peristalsis. Current data and recommendations allow for regular use in some patients (dose adjustment, monitoring for side effects). [21]

Step 2: Prescription Drugs

• Secretagogues (linaclotide, plecamer/plecanatide, lubiprostone): increase fluid secretion and facilitate stool passage. Recommended when background therapy is ineffective. [22]
• Prokinetic 5-HT₄ (prucalopride): Enhances colonic motility, useful in slow transit and incomplete response to PEG/stimulants. [23]
• Opioid-induced constipation: peripheral μ-antagonists (naloxegol, naldemedine, methylnaltrexone) are added to the usual step - they relieve intestinal inhibition by opioids without affecting analgesia. [24]

Step 3. Pelvic floor dyssynergia

The gold standard is biofeedback therapy with sphincter relaxation training and abdominal/pelvic floor coordination. This method is superior to laxatives and maintains its effectiveness in both older and younger patients. [25]

Surgery

Subtotal colectomy (without rectum) is possible only with proven colonic inertia, absence of dyssynergia and ineffectiveness of the entire conservative line - after a multi-stage evaluation in a specialized center. [26]

Table 2. What and when to prescribe (according to AGA/ACG 2023)

Class	Examples	Recommendation level
Osmotic agents	PEG (first line), lactulose	Recommended for chronic pulmonary disease (severe/moderate). [27]
Stimulants	Bisacodyl, senna, Na-picosulfate	Recommended/suggested; safe when used correctly. [28]
Mineral salts	Magnesium oxide	Proposed (conditionally). [29]
Secretagogues	Linaclotide, plecaman/plecanatide, lubiprostone	Recommended/suggested if step 1 is ineffective. [30]
Prokinetic	Prucalopride	Recommended as a next line. [31]

Myths and facts about laxative addiction

Myth: "Stimulant laxatives damage the intestinal nervous system, leading to addiction and the development of a 'catarrhal' colon."
What science says: Current reviews and pharmacological data do not confirm colon damage at recommended doses; safety and efficacy for long-term use in some patients are supported by new evidence and reflected in 2023 guidelines. Yes, cramping, diarrhea, and hypokalemia are possible with overdose and in vulnerable groups—so individual selection and medical supervision are essential. [32]

Myth: "Hormone tests, ultrasound, and colonoscopy are always necessary first.
" Fact: Without "red flags," these are unnecessary; a clinical assessment and initial treatment are sufficient. Colonoscopy is indicated for cancer screening or if alarming symptoms are present. [33]

Myth: "Without daily bowel movements, the body becomes 'poisoned.'"
Fact: Bowel frequency varies from three times a day to three times a week. Comfort, effortlessness, and the feeling of complete evacuation are more important. [34]

Myth: "Enemas and 'detoxes' are a safe way to clear the bowels."
Fact: Frequent enemas and 'cleansings' disrupt electrolytes and microbiota, increase dependence on the procedures, and delay proper diagnosis (e.g., dyssynergia). Step-by-step, evidence-based approaches are preferable. [35]