New Abdominal Pain that’s diffuse, felt all over, or mainly around the belly-button (“periumbilical”) would not be due to the other localized conditions we’ve described so far in the other areas of the abdomen (unless the pain radiates to a telltale location, e.g. to Right shoulder might suggest Gallbladder Disease). So when abdominal pain is felt more generally, no real specific place, we wind up either diagnosing something benign that usually gets better on its own [in which case it doesn’t really matter if our diagnosis isn’t exact], or sending the patient to surgery. The possibilities are:
Possible Causes of Acute Generalized Abdominal Pain
|xxxxCommon & Benign |
• Gastritis / Dyspepsia
• Muscle Strain
|xxxxRare & Catastrophic |
• Bowel Obstruction
• Peritonitis / Ruptured Bowel
• Bowel Ischemia (loss of
• Aortic Aneurysm (ruptured)
• Strangulated Hernia
• Diabetic Ketoacidosis (DKA)
|xxxx Keep In Mind |
• Early Appendicitis
xxxShould NOT Diagnose
NOTE: If Vomiting or Diarrhea are more significant than “pain”, refer to those symptom topics
First Step — Rule-out catastrophes. These may be obvious, like with a patient who walks doubled-over, has a fever, and on exam the abdomen is extremely tender to palpation & feels as hard as a board. Such patients gain a trip to the ER, as do those in extreme pain, even if the abdomen isn’t so tender on exam.
The rest of this discussion deals with the subtle, early presentations of catastrophic illness, which are more interesting and difficult.
** Bowel Obstruction may occur in patients who’d had any sort of previous abdominal surgery or radiation treatment (not just CT scans). Scars, called “adhesions,” cause either the large or small intestine to knot up. Without treatment, infection can occur, especially if the bowel ruptures; then the person can get septic (“blood poisoning”) and die. Sometimes bowel obstructions are due to conditions like undiagnosed Colon Cancer.
The generalized abdominal pain is accompanied by nausea, & usually vomiting [if not, the obstruction is so early, that if the diagnosis is missed, symptoms will get worse & the patient will return]. On exam, in addition to tenderness during palpation, we might hear abnormal sounds with our stethoscope (listening to the abdomen is rarely helpful; this is one of the exceptions).
Any such patient with new, unusual abdominal pain and nausea, especially if there’s a history of previous surgery or radiation treatment, deserves a simple abdominal x-ray (called a “plain film” or “KUB”, done both lying flat & standing upright). It’s easy to see the telltale dilated bowel or fluid levels. Plain x-rays of the abdomen are rarely helpful; this is one of the exceptions.
** Strangulated Hernias are a form of bowel obstruction. They’re not subtle — the hernia (lump of bowel) is very tender, accompanied by nausea and/or vomiting. They most commonly occur in the groin, possibly in old surgical scar sites, & rarely in the midline or right near the belly-button. It’s pretty obvious, and shouldn’t be a problem diagnostically.
** Early Peritonitis (infection spreading within the overall abdominal cavity), is a not-to-miss diagnosis. Bowel germs may spread from another disease like Appendicitis, Crohn’s disease, or an undiagnosed Cancer. Treatment requires IV antibiotics & especially surgery to drain the infection (see Diagram — Gastrointestinal System — Anatomy).
The key to diagnosing Peritonitis is finding tenderness despite every effort to distract the patient, absolutely every time we palpate. Tenderness when we jiggle or percuss the abdomen (tapping gently) is pretty suggestive. Any degree of fever raises the likelihood. When pain begins before nausea, we’re always concerned.
These physical exam findings are hard to ignore, and deserve a complete blood count (CBC), looking for significant elevation of white blood cells. We also want to observe the patient for a number of hours, to see if things get worse. We especially suspect possible peritonitis it in the elderly and other immunocompromised persons. Such patients are best managed in an ER, where they can get the extensive testing necessary, be watched long enough to see if symptoms progress, and receive rapid treatment if necessary.
A special type, called “Subacute Bacterial Peritonitis“, occurs in patients with advanced liver disease (cirrhosis and portal hypertension). They’re prone to having fluid accumulate in the abdomen (ascites), which is easy to breed germs. If such patients have new generalized abdominal pain, even if there’s no tenderness, we begin a work-up (often in an ER, where they can aspirate the ascites to tell if it’s infected).
** Diabetic Ketoacidosis (DKA) can cause abdominal pain, nausea / vomiting, sometimes severe enough to mimic a serious abdominal infection. It progresses rapidly, and can be fatal. Patients experience extreme thirst, thus drink a lot and pee a lot — key symptoms if we think to ask about them. The diagnosis is easily made by a simple urinalysis, which shows sugar and ketones (the acidity which can kill if it’s in the blood too). It’s trickier for persons who don’t know they have Type-1 Diabetes; indeed, the disease is usually diagnosed during the first episode of DKA.
The main diagnostic quandary is not thinking about it when a patient presents to us with severe nausea, vomiting, and/or abdominal pain. See also Diabetes.
** Vascular Catastrophes — Various lethal diseases of the blood vessels can cause abdominal pain (see Diagram — Circulatory System). They include:
- Abdominal Aortic Aneurysm (AAA) (which ruptures)
- Mesenteric Ischemia (loss of blood supply to abdominal arteries)
- Mesenteric Thrombosis (clots in abdominal veins)
These conditions occur in an older population with hypertension and other causes of atherosclerosis (hardening of the arteries). Beware the AAA among smokers over 60, and siblings of those who’ve had one. Arterial blood clots may afflict persons with metal heart valves or Atrial Fibrillation; vein clots occur in those with liver disease, or with unusual conditions that cause easy clotting.
KEY OBSERVATION — These Vascular Catastrophes often present with pain that’s out of proportion to findings on physical exam. There may be merely very slight tenderness to palpation of the belly. In up to 40% of persons with an AAA, we can’t feel the swollen aneurysm. So we send patients to the ER based on two simple criteria:
- Risk factors
- Sudden onset of new, severe abdominal pain
Immunocompromised Patients — People with weak immune systems may have terrible abdominal infections, but hardly feel ill. That’s because it’s our immune system that causes our fever and pain. We are always super-cautious when such patients get sick, tend to order more tests than usual, and are thus more likely to have an ER take over. They include:
|• kidney failure|
• liver failure (cirrhosis)
• active cancer
• rheumatologic diseases
|• Sickle Cell Disease|
• Immunosuppressive therapy
• some other chronic diseases
The same holds true for the Severely Mentally Ill (with psychosis), who can tolerate extreme levels of pain. When they do come in with a medical problem, we should worry.
An otherwise-healthy 78-year old lady once saw me for LLQ pain going on since the day before. She looked fine, didn’t seem ill at all. It might have been uncomplicated Diverticulitis, but I was nervous. So I sent her to the ER — her CT scan was negative, they gave her antibiotics anyway. The next day she returned to me with Zoster (Shingles). I had no regrets whatsoever.
But let’s say, like the vast majority of persons with recent onset of new, generalized abdominal pain, our patient 1) doesn’t look ill, and 2) doesn’t have significant tenderness when we palpate their abdomen. They aren’t immunocompromised, and don’t have risk factors for vascular catastrophes. Even if they’d had some sort of prior surgery, raising the possibility of bowel obstruction, we wouldn’t pursue it if there’s no nausea or vomiting [see “Clinical Pearl” below].
We might order a simple urinalysis, which would find new-onset diabetes. But our diagnosis for Generalized / Periumbilical Abdominal Pain will wind up as one of the following Benign Conditions:
** Dyspepsia is the most likely if the patient has a bloated feeling. As noted in our discussion of the upper abdomen, we’d give a trial of an antacid treatment.
** Gastritis can actually be a little more serious than Dyspepsia. It usually occurs in the Epigastric area, where Ulcers also occur, but sometimes can be a bit more generalized. The difference between the two is that on endoscopy, with Gastritis we see inflammation or even bleeding, while with Dyspepsia, the stomach looks completely normal. But treatment (with antacids) is exactly the same.
** Muscle Strain: a common cause of any abdominal pain. If there’s no tenderness while the patient lies relaxed, but there is while they flex their abs (like during a partial sit-up), we’ve made the diagnosis.
“NOT Gastroenteritis” — Why is this in our list? Gastroenteritis is an infection inside the lumen, i.e. the long digestive tube from mouth to anus (see Diagram – Gastrointestinal System). Viruses in the bowel cause prominent diarrhea; bacterial toxins in the stomach cause abrupt vomiting (see Differences Among Germs). Any pain is incidental — it’s not what motivates the patient to seek care.
If the situation is at all confusing to us, here’s a CLINICAL PEARL:
- With Gastroenteritis, the nausea / vomiting or diarrhea begin before the pain.
- When pain begins first (or at the same time as nausea / vomiting), we consider one of the other conditions or organs outside the lumen.
** Early Appendicitis — A perfect example. During the first 24 (maybe 48) hours of appendicitis, a vague pain begins in the upper- or mid-abdomen. A key symptom is loss of appetite. A key sign is subtle tenderness in the right lower quadrant (RLQ), despite every effort of the examiner to distract the patient. We may send such patients home from the office, but always warn them that if nausea begins, or the pain gets worse, or localizes to the RLQ, to go to an ER.
See also Acute Generalized Abdominal Pain for the clinician’s condensed thought-process when face-to-face with a patient.