The emergency physician encounters patients every day with some form of abdominal pain, and the patient with chronic abdominal pain remains a common medical and surgical problem. Recurring chronic abdominal pain that persists as long as several hours or several days, with the patient being entirely normal between attacks, may be particularly difficult to diagnose. These patients are sometimes dismissed as having a “functional” problem and are not investigated properly. It is vital to seek out the potential cause of this type of chronic abdominal pain, because specific and often curative treatment is available.

Abundant information is available concerning patients with acute abdominal pain, yet caring for patients with chronic or chronic recurrent abdominal pain is rarely taught or addressed. Caring for patients with chronic recurrent abdominal pain is not easy and is a diagnostic challenge, requiring the utmost of skill as a clinician. The history is critical to making the diagnosis, and subtle physical findings must not be overlooked. In addition, one must have a good working list of potential diagnoses to provide direction. Like any puzzle, if one has a systematic approach, then solving it is not so complicated.

One of the keys to solving the puzzle of the difficult diagnoses in patients with chronic recurrent abdominal pain is the pattern of pain. Bouts of pain with entirely normal intervals are usually explained by a discrete intermittent disorder of physiology. Examples include acute intermittent porphyria (AIP), familial Mediterranean fever (FMF), internal hernias, endometriosis, and occasionally choledocholithiasis. Chronic abdominal pain that is present most or all of the time is usually from a clear pathophysiologic abnormality, such as chronic pancreatitis or pancreatic or colonic malignancy. The control of intractable abdominal pain associated with diseases that cannot be satisfactorily treated is one of the most challenging and frustrating problems the clinician has to face. Examples include unresectable pancreatic carcinoma and chronic pancreatitis. Pharmacologic management, along with behavioral and psychological therapies, is frequently applied with some success. Neurosurgical and/or chemical ablation techniques may be required in select cases. Other causes of chronic recurrent abdominal pain may have no specific pathophysiologic abnormality. Functional dyspepsia and irritable bowel syndrome are examples. Pain arising from the abdominal wall frequently is misdiagnosed. Specific diagnoses include iatrogenic peripheral nerve injuries, hernias, myofascial pain syndromes, the rib tip syndrome, abdominal pain of spinal origin, and spontaneous rectus sheath hematoma. It is not uncommon to have peripheral nerve injuries following surgical procedures, such as hernia repair with injury or entrapment of the ilioinguinal nerve, resulting in chronic recurrent pain. Numerous psychiatric disorders are also associated with chronic recurrent abdominal pain. Diagnoses include primary affective disorders, somatization disorders, psychogenic (conversion) pain, hypochondriasis, anxiety states, substance abuse disorders, schizophrenia, chronic factitious disorder with physical symptoms (Munchausen's syndrome), and malingering.

Every practicing emergency physician should develop a base of information on which to draw when approaching patients with chronic recurrent abdominal pain. This review discusses the physiology of abdominal pain and then provides practical information on how to arrive at an appropriate disposition by means of a careful evaluation of clues from the history, physical examination, and diagnostic tests. A working differential diagnosis list is presented and pertinent points on disposition discussed. A few of the interesting diagnoses relating to chronic recurrent abdominal pain will be discussed in more detail.