Approach to periumbilical and lower abdominal pain: Clinical sciences

Abdominal pain is a symptom of many conditions, which can range from benign to serious ones that require surgical intervention. Based on the affected region of the abdomen, abdominal pain can be classified into right upper quadrant, left upper quadrant, right lower quadrant, and left lower quadrant. It can also be epigastric or periumbilical.

The first step in evaluating a patient with abdominal pain is to assess their ABCDE to determine if they are stable or unstable. If the patient is unstable, start acute management before doing any diagnostic workup. This means that you might need to stabilize their airway, provide supplemental oxygen, establish IV access, and continuously monitor hemodynamics.

Here’s a high yield fact! If an unstable patient presents with abdominal pain, be sure to rule out life-threatening conditions like acute mesenteric ischemia and perforated viscus, as well as abdominal aortic aneurysm.

On the other hand, for stable patients, your first step is to obtain a focused history and physical exam, or H&P for short. On history, you should characterize the pain based on its location, severity, and chronicity, and determine aggravating and alleviating factors as well as other associated symptoms.

Next, you should quickly assess for any signs of an acute abdomen. In this case, history may reveal recent abdominal or GI procedures such as EGD, colonoscopy, or surgery; as well as abdominal or GI cancer. In some cases, the patient will have a history of abdominal aortic aneurysm. On physical exam, you’ll usually find severe distension with rigidity, diffuse tenderness, rebound, and guarding.

Because an acute abdomen is a surgical emergency, you need to call the surgical team right away. You should also get bedside imaging, including an abdominal x-ray that may show free air or small or large bowel obstruction; and an abdominal ultrasound, which may show abnormality of the aorta and free fluid. Depending on your suspicion for underlying cause, the surgery team may take the patient for a possible exploratory laparotomy. In this case, exploratory laparotomy is considered both diagnostic and therapeutic. The intervention might reveal threatening conditions like abdominal sepsis, perforated viscus, ruptured abdominal aortic aneurysm, and even acute bowel infarction and necrosis.

Now, once you have ruled out an acute abdomen, the next step is to assess for other causes of abdominal pain. The location of pain on history and physical examination can be your best initial guide to narrow your differential diagnoses based on your clinical suspicion.

Let’s start with the causes of periumbilical abdominal pain, which include small bowel obstruction and infectious gastritis or enterocolitis. First, obtain a focused history and physical exam. Small bowel obstruction is one of those “not to miss” causes of periumbilical abdominal pain. These patients typically report crampy pain that is often associated with nausea, bilious vomiting, oral intolerance, and bowel changes like constipation and the more severe obstipation, where the person can’t pass gas or stool at all. Additionally, you might find some risk factors like elderly patients, patients with a history of abdominopelvic surgery, inflammatory bowel disease, or a hernia.

On exam, you might find abdominal distension with diffuse tenderness, hypertympanic sounds on percussion, and hyperactive bowel sounds on auscultation. In addition, remember to look for surgical scars and periumbilical or groin hernias during your exam! Then, you should order labs like CBC and CMP, which are usually normal but sometimes you might find leukocytosis, as well as signs of dehydration from vomiting, such as electrolyte abnormalities like hypernatremia.

All these findings should make you consider small bowel obstruction, so your next step is to order a CT scan of the abdomen and pelvis with oral contrast. Imaging typically shows dilated loops of the bowel with a transition point and distal collapsed bowel, as well as air-fluid levels. Additionally, you might see signs of the cause of the obstruction like the target sign of intussusception, most often in children; or portions of the small bowel within an umbilical hernia. So, if you see any of these on imaging, you can help you make a diagnosis of small bowel obstruction.

Another common cause of periumbilical abdominal pain is infectious gastritis or enterocolitis. Patients often report sudden onset of crampy pain, nausea, vomiting, diarrhea, and fever after ingesting raw or spoiled foods. Others might report sick contacts with similar symptoms, recent travel, or antibiotic use.

On a physical exam, you can expect to find a soft abdomen with mild tenderness on an otherwise healthy looking individual. If you see these findings in combination, you can diagnose infectious gastritis or enterocolitis. Remember this is a clinical diagnosis, and often does not warrant additional diagnostic tests.