Chronic Abdominal Pain Management

Introduction to May-Thurner Syndrome and Chronic Abdominal Pain

May-Thurner syndrome (MTS) is a vascular condition characterized by compression of the left common iliac vein, primarily affecting venous return from the left lower extremity, which can lead to venous stasis, thrombosis, and related complications, although it is not typically a primary cause of chronic abdominal pain 1

The American College of Radiology recommends considering mesenteric ischemia in patients with postprandial pain, fear of eating, and weight loss, especially those with atherosclerotic disease, as a potential cause of chronic abdominal pain 1
The Gut society suggests considering chronic intestinal dysmotility in patients presenting with abdominal pain, distension, bloating, early satiety, nausea, and vomiting as a cause of chronic abdominal pain 2
The American College of Radiology also recommends considering median arcuate ligament syndrome, which can cause celiac artery compression and abdominal pain, especially postprandial, in the differential diagnosis for chronic abdominal pain 3

CT venography (CTV) of the abdomen and pelvis can identify stenosis, occlusion, collaterals, and edema related to venous obstruction in suspected MTS, according to the American College of Radiology 4
Catheter venography with intravascular ultrasound (IVUS) is usually performed for definitive diagnosis before intervention in MTS, as per the American College of Radiology 4

Constipation leads to gut stasis, distension, and altered gut motility that directly triggers pain pathways, contributing to abdominal pain 2
Gut stasis causes abdominal distension and accumulation of fluid, leading to pain 2
Bacterial overgrowth due to stagnant intestinal contents causes gas, bloating, and pain 2
Visceral hypersensitivity may develop in patients, leading to heightened sensitivity to normal bowel distension 5
Central sensitization can occur due to persistent constipation, amplifying pain perception even with minimal stimulation 5

The pain associated with constipation typically presents as colicky or cramping abdominal pain, often in the lower abdomen, which worsens with eating and improves after bowel movements 2
When evaluating chronic abdominal pain potentially related to constipation, determine if pain improves with bowel movements or worsens with prolonged constipation, and assess for alarm features that might suggest other pathology 2

Regular exercise promotes bowel motility, according to the American Gastroenterological Association 6
Establishing a regular time for defecation helps regulate bowel movements, as recommended by the American Gastroenterological Association 6
Adequate hydration is essential for preventing constipation, as suggested by the European Society of Gastrointestinal Motility 6

Soluble fiber (ispaghula/psyllium) at 3-4g/day with gradual increase can help alleviate constipation, as recommended by the American Gastroenterological Association 6
Polyethylene glycol (PEG) is recommended as first-line therapy for constipation, according to the American Gastroenterological Association 6
Peppermint oil may be used for pain relief, as suggested by the European Society of Gastrointestinal Motility 6
Antispasmodics can be used for pain management, according to the American Gastroenterological Association 6
Tricyclic antidepressants (TCAs) like amitriptyline may be used for pain management, as recommended by the American Gastroenterological Association 6
Linaclotide (72-290mcg daily) can be used for constipation with abdominal pain, according to the European Society of Gastrointestinal Motility 6
Probiotics may improve global symptoms and abdominal pain, as suggested by the American Gastroenterological Association 6

Cognitive behavioral therapy (CBT), gut-directed hypnotherapy, and mindfulness-based stress reduction may be considered for persistent symptoms, according to the American Gastroenterological Association 6

Opioids should be avoided, as they worsen constipation and can lead to narcotic bowel syndrome with hyperalgesia, according to the American Gastroenterological Association 2, 6
Conventional analgesics are generally ineffective and may worsen symptoms, as suggested by the European Society of Gastrointestinal Motility 6
Ineffective treatments should be discontinued after 12 weeks, according to the American Gastroenterological Association 6