For patients with symptomatic constipation, it is appropriate, but not always necessary, to obtain a complete blood count, biochemical profile, serum calcium, glucose levels, and thyroid-stimulating hormone.

If the presentation is not clear or there is any concern about significant underlying disease, consider using diagnostic tests, such as urinalysis (to help rule out renal colic or urinary tract infection), an erythrocyte sedimentation rate (a clue to infection or inflammation), abdominal radiographs (to show free peritoneal air, bowel obstruction, or fecal impaction), and ultrasonography (for pyloric stenosis, malrotation and intussusception in children, or gallbladder and pelvic disorders in adults). CT imaging should be used to rule out any suspected intra-abdominal or retroperitoneal catastrophe. Adult patients with a change in bowel habits or hemoccult positive stool should be referred for colonoscopy to assess for malignancy.

If simple constipation is the problem and there is obstructing stool on rectal examination, disimpact the rectum by pulling out hard stool (scybala), and follow with one oil retention enema. This may be very painful and require parenteral analgesia. For dry, obstipated feces, repeated tap-water enemas or phosphate enemas should be administered once or twice daily until clear.

Disimpaction by the oral route, using medication, is noninvasive and more easily accepted by adolescents, who will often be reluctant to receive enemas. If there is no mechanically obstructing fecal impaction, this can also be done for adults. Magnesium citrate (Citro-Mag), 150 to 300 mL given once or divided doses for those 7 to 12 years old. For pediatric patients younger than 6 years, 2 to 4 mL/kg given once or in divided doses.

Disimpaction by means of a combination of the rectal route and the oral route has been shown to be effective.

Instruct the patient to return if symptoms do not resolve over the next 12 to 24 hours or to return immediately if the pain worsens.

Instruct the patient to drink plenty of fluids.

Instruct the patient that the recommended amount of dietary fiber is 20 to 35 g per day.

Suggest adding bulk fiber, 20 to 35 g total fiber intake per day, in the form of bran, psyllium (Metamucil), methylcellulose (Citrucel), or calcium polycarbophil (FiberCon tablets) for prophylaxis. The last two products are made from synthetic fiber and produce less gas. A high-fiber diet, however, does not benefit all patients with constipation. In general, patients with inadequate fiber intake should be advised (with the help of a dietitian) to increase their intake of natural fiber with fruit and vegetable servings.

When possible, medications that may be constipating should be discontinued or replaced. These medications include narcotic analgesics, antacids containing aluminum and calcium, antidepressants, diuretics, nutritional supplements such as iron and calcium, anticonvulsants, antispasmodics, antiparkinson drugs, antihypertensive agents such as calcium channel blockers, and sedatives.

Osmotic agents with laxative effects include sorbitol solution 70% (30 to 150 mL or 1 to 2 mL/kg as single adult dose) or lactulose (Cephulac, Chronulac) (30 to 150 mL daily, may increase to 60 mL daily if necessary). In recent years, the use of over-the-counter polyethylene glycol 3350 without electrolytes (MiraLax), (17 g [1 heaping tablespoonful] of powder dissolved in 8 oz of water, juice, soda, coffee, or tea once daily, titrated to effect with a maximum of 34 g per day) has become increasingly popular. It is relatively expensive but generally has fewer side effects. Because it is virtually tasteless, it has led to better compliance with treatment. Polyethylene glycol (e.g., GoLYTELY) is another option, and is supplied in 14-oz and 26-oz containers as a powder to be administered after dissolution of 1 heaping tablespoon in 4 to 8 oz of water, juice, soda, coffee, or tea qd.

Additionally, bisacodyl (Dulcolax), 5 to 15 mg as single adult dose, or senna (Senokot), 15 mg once daily, are stimulant laxatives that can be given at bedtime and are available over the counter. Both sorbitol and senna are less costly than lactulose and have been shown to be at least as efficacious, if not better.

Functional constipation in infants and toddlers is defined as at least 2 weeks of scybalous, pebble-like, hard stools—or firm stools two or fewer times per week—in the absence of structural, endocrine, or metabolic disease.

Constipation in infants and preschool children is usually treated first with sorbitol-containing juices, such as prune, pear, and apple juice; the addition of pureed fruits and vegetables; formula changes; or treatment with a food product with a high sugar content, such as barley malt extract or corn syrup. If, despite these dietary changes, the stool is still hard and painful to evacuate, osmotic laxatives, such as milk of magnesia, 0.5 to 1 mL/kg body weight/day, or polyethylene glycol 3350 without electrolytes (MiraLax), 1 to 1.5 g/kg body weight/day, are easily administered by parents and well-accepted by children. They have a 92% success rate. Glycerin suppositories can be also be effective. Avoid mineral oil in infants, those with neurologic difficulties, and those with gastoesophageal reflux disease (GERD) because of the risk of aspiration pneumonitis. In addition, avoid enemas and stimulant laxatives, such as senna or bisacodyl, in infants.

If the problem is chronic or recurrent or associated with alternating constipation and diarrhea, consider irritable bowel syndrome (IBS). IBS is characterized by chronic abdominal pain, altered bowel habits, and no organic cause; thus it is a diagnosis of exclusion. The most distinguishing trait of IBS is the presence of discomfort or pain associated with defecation. The Rome III criteria of 2005 to 2006 include the following criteria for IBS: at least 3 months of symptoms, with onset at least 6 months previously of recurrent abdominal pain or discomfort associated with two or more of the following:

Improvement with defecation; and/or

Onset associated with change in frequency of stool; and/or

Onset associated with a change in form (appearance) of stool.

If the patient meets the Rome III criteria, if routine testing shows no abnormalities, and if the patient has no warning signs of more serious disease, then you can initiate treatment for IBS and provide follow-up in 3 to 6 weeks (sooner if symptoms change dramatically or the patient’s condition deteriorates).

IBS is a chronic condition without known cure. A meticulous dietary history, as it relates to symptoms, can be helpful. Dietary interventions such as a lactose-free diet, restriction of carbohydrates, avoidance of gluten, and avoidance of foods that produce gas may be undertaken.

For constipation-predominant IBS, you can give synthetic bulk fiber as described earlier.

Psychological therapy has been found to have some efficacy in IBS symptom reduction, as noted in the 2009 American College of Gastroenterology Task Force on Irritable Bowel Syndrome, which also provides further guidelines for management of this disorder.

The use of pharmacologic agents may also be considered. Antidepressants, such as SSRIs or low-dose TCAs, may be useful in adults with severe, unrelenting symptoms. Antispasmodic drugs, such as dicyclomine (20 mg PO, 4 times daily prn for nongeriatric adult) and hyoscyamine (0.125 to 0.25 mg PO or sublingual tid prn for adult, maximum 1.5 mg/24 h) may provide short-term relief. 5-Hydroxytryptamine (serotonin)-3 (5-HT₃) receptor antagonists such as alosetron (Lotronex), for female patients with diarrhea-predominant IBS, were removed from the market because of problems with ischemic colitis and severe constipation, but are now available with tight restrictions. Tegaserod (Zelnorm), a partial 5-HT₄ receptor agonist approved for constipation-variant IBS was removed from the market in 2007. Lubiprostone for patients with IBS with constipation has been approved, but there is a lack of controlled studies and long-term safety concerns exist.

Rifaximin is a nonabsorbable antibiotic that has shown modest benefit in studies with relatively short-term follow-up for those with IBS and bloating.

If there is weight loss, anemia, occult blood in the stool, abdominal distension or mass, or a family history of colon cancer, refer the patient for colonoscopy and gastroenterology consultation.

For infant colic (defined as crying for a minimum of 3 hours daily 3 days per week for the previous 3 weeks, without weight loss, vomiting, or diarrhea), there is no “magic bullet.” Use of whey hydrolysate milk is considered likely to be beneficial. Other therapies are of uncertain effectiveness. You may instruct the parents to administer for infants, 2 mL of 24% solution of sucrose in distilled water and for neonates, 0.2 mL of 24% solution, with each episode for a 1- to 2-day trial. If this is not successful, a higher concentration of sucrose may be more effective. Probiotics (Lactobacillus reuteri) have been shown to be beneficial in two randomized trials, with no ill effects observed. However, these are not regulated by the Food and Drug Administration. Homeopathic remedies, simethicone and lactase have no proven benefits.

With breast-feeding mothers, there is a possible therapeutic benefit from eliminating milk products, eggs, wheat, and nuts from the mother’s diet.

Some studies suggest that casein hydrolysate formulas (considered hypoallergenic) or replacement of cow’s milk formula with a soy-based formula may be beneficial; a trial period of formula substitution can be recommended.

Above all, parents need reassurance that their baby is healthy and that colic is self limited (80% to 90% of infants have symptom resolution by 4 months of age). There are no long-term adverse effects. The potential for child abuse is a real one; parents with crying infants have been known to hurt their babies. Parents should be given reassurance and empathy and have their coping mechanisms addressed; they should be counseled to take breaks from the colicky infant and employ actions to relieve stress. One study concluded that a home-based nursing intervention program reduced both parental stress and overall infant crying time.

What Not To Do:

Do not discharge the patient with significant abdominal pain without 1 to 2 hours of observation and two abdominal examinations. Many abdominal catastrophes may appear improved for short periods, only to worsen in an hour or two.

Do not add fiber supplements without an adequate intake of fluids. Otherwise, they may actually exacerbate symptoms.