Case study: Gastrointestinal function
R.H. is a 74-year-old black woman, who presents to the family practice clinic for a scheduled appointment. She complains of feeling bloated and constipated for the past month, sometimes going an entire week with only one bowel movement. Until this episode, she has been very regular all of her life, having a bowel movement every day or every other day. She reports straining most of the time and it often takes her 10 minutes at a minimum to initiate a bowel movement. Stools have been extremely hard. She denies pain during straining. A recent colonoscopy was negative for tumors or other lesions. She has not yet taken any medications to provide relief for her constipation. Furthermore, she reports frequent heartburn (3–4 times each week), most often occurring soon after retiring to bed. She uses three pillows to keep herself in a more upright position during sleep. On a friend’s advice, she purchased a package of over-the-counter aluminum hydroxide tablets to help relieve the heartburn. She has had some improvement since she began taking the medicine. She reports using naproxen as needed for arthritic pain in her hands and knees. She states that her hands and knees are extremely stiff when she rises in the morning. Because her arthritis has been getting worse, she has stopped taking her daily walks and now gets very little exercise.
Case study questions
- In your own words, define constipation and name the risk factors that might lead to constipation. List recommendations you would give to a patient who is suffering from constipation. You might use a previous experience.
- Based on the clinical manifestations in R.H.’s case study, name and explain the signs and symptoms that are compatible with the constipation diagnosis. Complement your list with signs and symptoms not present in the case study.
- Sometimes, as an associated diagnosis and a complication, patients with constipation could have anemia. Would you consider that possibility based on the information provided in the case study?
1. Defining constipation, risk factors and recommendations
Definition
Constipation is difficult, infrequent or incomplete passage of stool. In simple terms, a person is constipated when bowel movements become less frequent than is normal for them, stools are hard and dry, and passing them requires straining or feels unfinished. Normal frequency ranges widely, from three times a day to three times a week, so a change from the person’s usual pattern matters as much as the number of bowel movements.
Clinicians often use the Rome IV criteria for functional constipation. These require two or more of the following in more than 25% of bowel movements: straining; lumpy or hard stools (Bristol Stool Form Scale types 1–2); a sensation of incomplete evacuation; a sensation of anorectal blockage; manual maneuvers to help defecation; or fewer than three spontaneous bowel movements per week. Symptoms must be present for the last 3 months, with onset at least 6 months before diagnosis (Mearin et al., 2016; Lewis & Heaton, 1997). R.H.’s symptoms began only a month ago, so hers is a new-onset change in bowel habit that needs a search for secondary causes, especially medications.
Risk factors
| Category | Risk factors | Present in R.H.? |
|---|---|---|
| Age and sex | Older age (slower colonic transit, weaker abdominal and pelvic muscles); female sex | ✓ 74-year-old woman |
| Lifestyle | Low fiber intake, low fluid intake, physical inactivity, ignoring the urge to defecate, changes in routine | ✓ Stopped daily walks; diet and fluids should be assessed |
| Medications | Aluminum- and calcium-containing antacids, opioids, anticholinergics, iron and calcium supplements, calcium channel blockers, diuretics, some antidepressants | ✓ Aluminum hydroxide, a well-known constipating antacid, started recently |
| Medical conditions | Hypothyroidism, diabetes, hypercalcemia, hypokalemia, Parkinson’s disease, stroke, spinal cord injury, depression, irritable bowel syndrome | Not stated; should be screened |
| Structural and anorectal | Colorectal tumors, strictures, pelvic floor dysfunction, rectocele, hemorrhoids, anal fissures | Colonoscopy negative for tumors |
| Mobility and pain | Arthritis, immobility, difficulty reaching the toilet | ✓ Worsening arthritis limits activity |
Key insight: The timing is telling. R.H. was “very regular all of her life” until about a month ago, around the same time she began taking aluminum hydroxide for heartburn and stopped her daily walks because of arthritis. Aluminum slows intestinal motility and binds with phosphate, producing hard stools. Together with inactivity, it is the most likely cause of her new constipation.
Recommendations for a patient with constipation
- Review medications: ask the provider or pharmacist about stopping aluminum hydroxide and treating heartburn another way (see below). Review all over-the-counter products and supplements.
- Increase dietary fiber gradually to about 25–30 g per day: whole grains, beans, vegetables, fruit, prunes and kiwifruit. Add fiber slowly to limit gas and bloating, or use a fiber supplement such as psyllium.
- Drink adequate fluids, about 1.5–2 liters a day unless restricted, especially when increasing fiber.
- Stay active: joint-friendly exercise such as water aerobics, stationary cycling, chair exercises or short walks after taking arthritis medication. Physical therapy can help maintain mobility.
- Establish a bowel routine: sit on the toilet at the same time each day, ideally 15–30 minutes after breakfast, to use the gastrocolic reflex. Never ignore the urge to go.
- Use proper positioning: place a footstool under the feet so the knees are higher than the hips. This straightens the anorectal angle and reduces straining.
- Use laxatives if lifestyle changes are not enough, as recommended by the provider. Guidelines support polyethylene glycol (PEG 3350) as a first-line osmotic laxative, with stimulant laxatives such as senna or bisacodyl for short-term or rescue use. Magnesium-containing laxatives should be avoided or used carefully in older adults with reduced kidney function (Chang et al., 2023).
- Know the red flags and report them promptly: blood in the stool, black stools, unintentional weight loss, severe abdominal pain, vomiting, or no bowel movement with abdominal swelling.
Example from practice (illustrative): An older adult admitted after hip surgery developed constipation from opioids and immobility. A bowel regimen with scheduled senna and PEG, warm prune juice at breakfast, early mobilization with physical therapy, and a bedside commode with a footstool restored regular bowel movements within three days. This shows how medication review, mobility and routine work together.
Addressing R.H.’s heartburn safely
R.H.’s nighttime heartburn suggests gastroesophageal reflux disease (GERD). Rather than aluminum hydroxide, recommend these measures and a provider review (Katz et al., 2022):
- Avoid eating within 2–3 hours of bedtime.
- Raise the head of the bed with blocks or a wedge, rather than stacking pillows, which bends the abdomen.
- Limit trigger foods, and lose weight if overweight.
- Consider an H2 blocker or a proton pump inhibitor if prescribed.
- Note that naproxen can worsen reflux and damage the stomach lining. Discuss safer arthritis pain options, such as acetaminophen or topical NSAIDs, and evaluation of the arthritis itself.
2. Signs and symptoms compatible with constipation in R.H.
Present in the case
| Sign or symptom | Explanation |
|---|---|
| Infrequent bowel movements (as few as 1 per week) | Well below her usual daily or every-other-day pattern, and below the threshold of 3 per week. Slowed colonic transit allows more water absorption (Rogers, 2023). |
| Hard stools | The longer stool stays in the colon, the more water is absorbed, producing hard, dry stools (Bristol types 1–2). |
| Straining most of the time | Hard stools are difficult to pass and need more abdominal pressure. Straining in more than 25% of bowel movements is a Rome IV criterion. |
| Prolonged time to start a bowel movement (10 minutes or more) | Reflects difficult evacuation, which may involve hard stool or reduced rectal sensation and muscle strength with age. |
| Bloating | Retained stool and gas cause a feeling of fullness and abdominal distension. |
| Change from her lifelong bowel pattern | A new change in bowel habit in an older adult always needs evaluation. Her recent negative colonoscopy is reassuring. |
| Contributing factors | Aluminum hydroxide use, physical inactivity due to arthritis, and older age. |
Note: R.H.’s nighttime heartburn and her need for three pillows point to GERD, a separate but related gastrointestinal problem, and they explain why she began taking the constipating antacid.
Signs and symptoms not present in the case (to assess)
- Abdominal pain or cramping (she denies pain with straining)
- A sensation of incomplete evacuation, or of blockage in the rectum
- Needing to use fingers (manual maneuvers) or press on the perineum to pass stool
- Palpable stool in the abdomen, or abdominal distension on examination
- Decreased appetite, nausea or early fullness
- Fecal impaction with paradoxical overflow diarrhea or fecal incontinence, a common complication in older adults
- Hemorrhoids, anal fissures or rectal bleeding from straining
- Rectal prolapse
- Headache, fatigue or malaise
- Urinary retention or urinary tract infection from a full rectum pressing on the bladder
- Red flags requiring further evaluation: blood in the stool, black stools, unintentional weight loss, iron-deficiency anemia, family history of colorectal cancer, or fever
3. Should anemia be considered?
Yes. The case does not give a hemoglobin value or symptoms of anemia, but several factors make it a reasonable possibility that should be checked:
- NSAID use (naproxen): NSAIDs can cause gastritis, peptic ulcers and occult (hidden) gastrointestinal bleeding, a common cause of iron-deficiency anemia in older adults. The risk is higher in people over 65.
- GERD and possible esophagitis: chronic reflux can inflame the esophagus and cause slow blood loss. Her colonoscopy examined only the lower GI tract, so an upper GI source has not been ruled out.
- Antacids and reduced acid: raising stomach pH, with antacids or long-term acid suppression, reduces the absorption of non-heme iron and possibly vitamin B12.
- Straining: repeated straining can cause hemorrhoids or anal fissures that bleed.
- Possible inflammatory arthritis: severe morning stiffness in the hands and knees may suggest an inflammatory arthritis such as rheumatoid arthritis rather than osteoarthritis. This can cause anemia of chronic inflammation.
- Shared cause: hypothyroidism can cause both constipation and anemia, and is common in older women.
- Nutrition: older adults with reduced activity and changing diets may have low iron, folate or B12 intake.
Recommended assessment: ask about fatigue, weakness, shortness of breath, dizziness, black stools and pallor. Examine for pallor of the conjunctivae and nail beds, adjusting assessment for darker skin. Order a CBC, iron studies (ferritin), B12 and folate, TSH, a metabolic panel (calcium, potassium, glucose, kidney function) and a stool test for occult blood. If iron-deficiency anemia is found, an upper endoscopy may be needed to look for an NSAID-related ulcer or esophagitis. If iron supplements are prescribed, plan ahead for their constipating effect.
Summary
R.H.’s new constipation, with infrequent, hard stools, straining, prolonged evacuation and bloating, is most likely caused by aluminum hydroxide antacid use combined with reduced physical activity from worsening arthritis, on top of age-related changes. Management should include medication review, safer treatment of her GERD and arthritis pain, more fiber and fluids, joint-friendly activity, a bowel routine and, if needed, osmotic laxatives. Because of her NSAID use, reflux, straining and possible inflammatory arthritis, anemia should be considered and screened for, even though the case does not report it.
Note: This case analysis is for educational purposes. Medication changes and diagnostic testing should be directed by the patient’s healthcare provider.
References
Chang, L., Chey, W. D., Imdad, A., Almario, C. V., Bharucha, A. E., Diem, S., Greer, K. B., Hanson, B., Harris, L. A., Ko, C., Murad, M. H., Patel, A., Shah, E. D., Lembo, A. J., & Sultan, S. (2023). American Gastroenterological Association–American College of Gastroenterology clinical practice guideline: Pharmacological management of chronic idiopathic constipation. American Journal of Gastroenterology, 118(6), 936–954. https://doi.org/10.14309/ajg.0000000000002227
Katz, P. O., Dunbar, K. B., Schnoll-Sussman, F. H., Greer, K. B., Yadlapati, R., & Spechler, S. J. (2022). ACG clinical guideline for the diagnosis and management of gastroesophageal reflux disease. American Journal of Gastroenterology, 117(1), 27–56. https://doi.org/10.14309/ajg.0000000000001538
Lewis, S. J., & Heaton, K. W. (1997). Stool form scale as a useful guide to intestinal transit time. Scandinavian Journal of Gastroenterology, 32(9), 920–924.
Mearin, F., Lacy, B. E., Chang, L., Chey, W. D., Lembo, A. J., Simren, M., & Spiller, R. (2016). Bowel disorders. Gastroenterology, 150(6), 1393–1407. https://doi.org/10.1053/j.gastro.2016.02.031
Rogers, J. L. (Ed.). (2023). McCance & Huether’s pathophysiology: The biologic basis for disease in adults and children (9th ed.). Elsevier.
You can also explore more resources on our website.
