Explaining Unexplained Abdominal Pain by Katie E. Golden, MD

Abdominal pain is a common symptom that brings patients to the emergency department (ED) for evaluation. It is also common that our ED workup does not find an identifiable cause, and patients are discharged home without a clear diagnosis. This requires the patient to closely monitor their symptoms, follow up with their regular doctor or a specialist, or even return to the ED if their symptoms worsen. This can be an understandably frustrating situation for patients. We thus want to take the time to explain precisely the tests we can run in the ED, the potential for conditions that require outpatient follow up for diagnosis, and guidance on when a patient should return to the ED for unexplained abdominal pain.

Let’s begin by reviewing the tests we perform for patients in the ED for abdominal pain.

While the list of conditions that cause abdominal or pelvic pain is infinite, the emergent conditions that require prompt diagnosis are more finite (fortunately for both ED doctors and patients). Testing in the ED typically begins with lab work: we check blood counts, electrolytes, kidney function, liver function, and perform an analysis of the urine. While this can sometimes be the only testing that is required to make a diagnosis or rule out an emergency, we typically also consider obtaining a CT scan of the abdomen and pelvis. This test gives us a detailed picture of all the organs from the lower part of the chest to the hips and allows us to efficiently diagnose the conditions requiring immediate treatment. This includes life-threatening infections, bowel obstructions, abnormal fluid or bleeding, kidney stones, masses or tumors, abnormalities of the blood vessels that run through the abdomen, the list goes on. We will also sometimes obtain an ultrasound instead of a CT scan, which is particularly useful at evaluating the gallbladder, ovaries and uterus, and testicles.

While these tests are designed to efficiently and accurately identify abdominal and pelvic emergencies, the list of non-life-threatening diagnoses that can cause pain is much longer, and unfortunately requires specialists and testing that we do not have in the ED. Examples of conditions that we would not diagnose on CT scan or ultrasound include viral infections (‘the stomach flu’), inflammation or ulcers in the stomach lining, inflammatory bowel disease (such as Crohn’s Disease or Ulcerative Colitis), irritable bowel syndrome or maldigestion, pelvic floor dysfunction, strains and spasms of the muscles in the back and abdomen, to name just a few. It is also worth mentioning that it is common for psychological stress to manifest in real, severe, and debilitating abdominal pain. Many patients do not realize that the same chemicals that regulate our brain and response to stress (dopamine, serotonin, and norepinephrine or ‘adrenaline’) are the same chemicals that regulate our intestinal function. So just the same way a difficult circumstance in our lives can trigger feelings of stress and anxiety, it can just as easily cause pretty significant abdominal pain instead.  Research suggests this may be a more frequent cause of abdominal pain than we currently appreciate, especially when a patient has persistent symptoms and extensive testing does not reveal any obvious cause.

When our ED workup does not reveal a clear explanation for abdominal pain, the ED clinician can sometimes provide some guidance on other potential causes of the pain and the necessary specialists and testing needed for further evaluation. If a patient’s symptoms are suggestive of inflammatory bowel disease, for example, we may provide a referral to a gastroenterologist, who can perform a colonoscopy for evaluation. One of the most useful diagnostic tools that we do not have at our disposal in the emergency room, however, is time. Many cases of unexplained abdominal pain will resolve on their own and are likely due to a transient period of maldigestion. Other conditions will progress and evolve over time, hopefully revealing symptoms that can help doctors identify the problem. Every ED clinician hopes to be able to diagnose and treat the cause of a patient’s pain, providing immediate relief and a resolution to the patient’s discomfort. More often, unfortunately, it takes time to identify the root cause of a patient’s symptoms.

In the meantime, we want to make sure our patients understand that following points if they are leaving the emergency department with unexplained abdominal pain:

  • Please consider the clinicians’ recommendations regarding follow-up, whether it be a primary care doctor or a specialist. Ongoing and repeated evaluation is often necessary to reach a diagnosis, and we give these recommendations sincerely and in the patient’s best interest.

  • It is important the patient consider returning for repeat evaluation if they have worsening symptoms, especially if the pain is accompanied by a new fever, repeated episodes of vomiting and inability to keep down fluids, frequent diarrhea, or bleeding from the intestine. As mentioned, some diagnoses cannot be made initially, but the evolution of the underlying condition and the resultant development of new symptoms requires re-evaluation. Appendicitis is a good example of a condition that can sometimes require re-evaluation . . .

  • Your clinician may speak to you about the possibility of early appendicitis. An appendix, in the early stages of appendicitis, can appear normal on an initial CT scan (the way we diagnose this condition). If the patient presented for pain in the right lower abdomen or around the belly button, and after going home the pain continues to worsen (or is accompanied by the symptoms mentioned above) then they must please pay attention to their clinician’s warning and come back for re-evaluation. A repeat CT scan may be required to make the diagnosis.

  • Patients often ask about a prescription medication when going home with ongoing symptoms. Prescription pain medication, more specifically opioid medications, are rarely advisable for abdominal pain. While they may provide temporary relief, these medicines work by binding to receptors in the intestine that can ultimately worsen, rather than help, the pain (not to mention cause severe constipation, nausea, vomiting, etc). Additionally, if there is no clear diagnosis for a patient’s pain, we do not want them to stay at home with worsening symptoms, relying on strong pain medication to avoid a repeat visit. If the pain advances to the point that standard, over the counter medications, are ineffective, we hope the patient will seek urgent re-evaluation at their nearest ED.