Postural Orthostatic Tachycardia Syndrome (POTS) is a medical condition that affects the autonomic nervous system, the body’s control center for involuntary functions. Many individuals with POTS experience gastrointestinal issues, which can be a significant part of their condition. These digestive problems include nausea, vomiting, bloating, diarrhea, constipation, and abdominal pain.
Understanding Postural Orthostatic Tachycardia Syndrome
POTS is a disorder of the autonomic nervous system (ANS), which regulates automatic bodily processes like heart rate, blood pressure, digestion, and body temperature. In POTS, the ANS does not function properly, particularly when changing from a reclining to an upright position. This malfunction leads to characteristic symptoms.
Upon standing, a person with POTS experiences an abnormal increase in heart rate, often by 30 beats per minute (bpm) or more within 10 minutes, or a heart rate exceeding 120 bpm. This rapid heart rate can be accompanied by lightheadedness, dizziness, fatigue, brain fog, headaches, chest pain, and shortness of breath. These symptoms are generally worse when upright and often improve upon lying down.
How POTS Impacts Digestion
The autonomic nervous system plays a significant role in digestive processes, including the movement of food through the gastrointestinal (GI) tract, blood flow to the gut, and the release of digestive enzymes. In POTS, autonomic dysfunction can disrupt these operations, leading to gastrointestinal abnormalities. One primary mechanism involves altered blood flow to the digestive system.
When a person with POTS stands up, blood tends to pool in the lower extremities and abdominal area, a phenomenon known as splanchnic blood pooling. This pooling reduces the amount of blood returning to the heart and, subsequently, to other organs, including the gut. Reduced blood flow to the GI tract can impair its function, affecting motility and absorption.
Autonomic dysfunction in POTS can interfere with the enteric nervous system, which controls gut motility. This can result in either delayed gastric emptying (gastroparesis) or rapid gastric emptying. In gastroparesis, the stomach muscles contract inefficiently, slowing the movement of food into the small intestine. Rapid gastric emptying involves food moving too quickly from the stomach. Both conditions can lead to digestive discomfort and nutritional deficiencies.
Common Digestive Symptoms and Related Conditions
Individuals with POTS frequently report a range of gastrointestinal symptoms. Nausea and abdominal pain are among the most prevalent non-cardiovascular complaints, affecting approximately 69% of POTS patients. Other common symptoms include bloating, vomiting, early satiety (feeling full quickly), constipation, and diarrhea. These symptoms can arise from the motility issues caused by autonomic dysfunction.
Delayed gastric emptying can lead to symptoms like nausea, vomiting, bloating, and a sensation of fullness. Rapid gastric emptying can also cause nausea, bloating, and abdominal pain. The severity and type of GI issues can vary, with rapid gastric emptying occurring in up to 48% of cases, while delayed gastric emptying occurs in up to 18% of patients.
Co-occurring Conditions
Ehlers-Danlos Syndrome (EDS)
This inherited connective tissue disorder is often seen alongside POTS. In EDS, the connective tissue that provides structure to the GI tract can be abnormally stretchy or fragile, potentially leading to motility issues and other digestive complaints.
Mast Cell Activation Syndrome (MCAS)
MCAS is frequently observed with POTS and EDS. It involves mast cells, a type of immune cell, releasing excessive amounts of inflammatory chemicals like histamine. This overactivation can cause gastrointestinal distress such as abdominal pain, diarrhea, nausea, and reflux. The inflammation triggered by MCAS can directly impact gut function.
Strategies for Managing Stomach Issues
Managing the digestive symptoms associated with POTS often involves a multifaceted approach, combining dietary modifications, lifestyle adjustments, and medical interventions. Eating smaller, more frequent meals throughout the day can be beneficial. Large meals can exacerbate POTS symptoms because digestion diverts more blood to the GI organs, reducing circulation elsewhere.
For those experiencing gastroparesis, a low-fat and low-fiber diet may be recommended, as fat and fiber can further slow stomach emptying. Some individuals find that consuming liquid or pureed meals is easier to digest. For rapid gastric emptying, meals higher in fat and fiber might help slow transit. Increasing fluid and sodium intake is generally recommended for POTS patients to help manage blood volume, which can also indirectly improve GI symptoms.
Medical interventions can also play a role in managing digestive symptoms. Prokinetic medications, such as metoclopramide, are sometimes prescribed to stimulate contractions in the GI tract and promote gastric emptying for gastroparesis. Antiemetics can help reduce nausea and vomiting. Medications for constipation, such as prucalopride or linaclotide, or for diarrhea may also be used depending on the predominant bowel habit. Working closely with healthcare professionals, including dietitians, is important for developing a personalized treatment plan.