What Pharmacists Can Ask When Diarrhea Keeps Coming Back

Imagine a patient reaching for another box of loperamide (Imodium). It helped for a day or 2, but the diarrhea came back. As the pharmacist asks how long it has been happening, the patient mentions something they had previously considered unrelated: their face sometimes gets hot and red during the same episodes. That detail changes what the pharmacist can pass along when recommending medical evaluation.

November 10 marks NET Cancer Day, when the International Neuroendocrine Cancer Alliance (INCA) calls for earlier recognition of neuroendocrine tumors (NETs). INCA’s 2026 campaign cites a global patient and caregiver survey that found an average of 5 years between initial symptoms and diagnosis. For community pharmacists, the awareness day points to a familiar encounter: a patient keeps returning for symptom relief, and the pharmacist has a chance to ask what happens between visits.¹

Establish the Timeline

Start with when the diarrhea began, how often it recurs, and whether it ever fully resolves. A patient who says they have had diarrhea for 2 days may be describing the current episode of a problem that has come and gone for weeks. Stool frequency and appearance, urgency, and whether symptoms wake the patient at night give the receiving clinician a clearer picture. Asking about the person’s usual bowel habits can also clarify how far the current pattern departs from their baseline. The OTC loperamide label directs patients to stop use and seek medical advice if diarrhea lasts more than 2 days or worsens.^2,3

Ask how much loperamide the patient has taken and how often they restart it. Relief that lasts until the next episode is worth recording alongside the duration of the underlying problem. That history helps distinguish a single bout of diarrhea from a recurring pattern that has been managed in short stretches.

Ask What Happens During an Episode

A broad question about what else happens during the episode can surface symptoms the patient has been tracking separately. With some NETs, tumor-released substances can cause carcinoid syndrome, which can include diarrhea, flushing, and wheezing. The syndrome occurs in a minority of patients with NETs, and recurrent diarrhea has a broad differential. Ask when the flushing occurs and whether it coincides with the diarrhea so the patient can describe the pattern during evaluation.^3,4

Review What Changed in the Medication List

Ask about new prescriptions, dose changes, and products the patient buys without a prescription. Metformin, magnesium-containing antacids or laxatives, and antibiotics are examples of drugs or products that can contribute to diarrhea. Compare the start date of a possible contributor with the onset of symptoms. If the timing suggests a prescription drug could be involved, share that observation with the prescriber so it can be considered alongside the rest of the history.³

Make the Referral Specific

Check for findings that warrant prompt medical attention. Bloody or black stools, severe abdominal pain, high fever, and signs of dehydration call for immediate contact with a clinician. Unintentional weight loss is another finding to flag during referral. For a patient with recurrent symptoms, give a clear next step, such as contacting their primary care clinician for evaluation, and explain which details to bring to that visit.^3,5

For the patient at the counter, the handoff might document several weeks of intermittent watery diarrhea, brief relief with loperamide, and facial flushing during some episodes. Add any recent medication changes and the patient’s reported OTC use. If the evaluating clinician suspects carcinoid syndrome, the workup may include a 24-hour urine test for 5-hydroxyindoleacetic acid. The decision to pursue testing depends on the clinical assessment.⁴

The patient came in to manage another episode. They can leave knowing whom to contact and how to describe what has been happening between pharmacy visits. A short conversation at the counter can turn a series of isolated purchases into a symptom history the next clinician can use.

REFERENCES

1. International Neuroendocrine Cancer Alliance. NET Cancer Day 2026 campaign toolkit. Accessed November 10, 2026. https://incalliance.org/ncd-2026/campaign-toolkit-2026/

2. Imodium A-D (loperamide hydrochloride) tablets. Drug Facts. DailyMed. Updated September 23, 2025. Accessed November 10, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=01da76d0-1979-4c45-9d39-c72ae4e4ffe2

3. Burgers K, Lindberg B, Bevis ZJ. Chronic diarrhea in adults: evaluation and differential diagnosis. Am Fam Physician. 2020;101(8):472-480

4. National Cancer Institute. Gastrointestinal neuroendocrine tumors treatment (PDQ®)—health professional version. Accessed November 10, 2026. https://www.cancer.gov/types/gi-neuroendocrine-tumors/hp/gi-neuroendocrine-treatment-pdq

5. National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms and causes of diarrhea. Accessed November 10, 2026. symptoms-causes