Endometriosis is a condition where tissue similar to the lining inside the uterus grows elsewhere in the body, most often in the pelvis. This misplaced tissue responds to hormonal changes, leading to inflammation, pain, and the formation of scar tissue. While primarily known for causing severe pelvic pain, many people also report a range of gastrointestinal (GI) issues, including nausea and vomiting. This article explores the specific reasons behind this common experience.
Confirming the Connection to GI Symptoms
Endometriosis is strongly linked to a variety of gastrointestinal complaints, including nausea and vomiting. Studies suggest that up to 90% of individuals with endometriosis experience some form of GI symptom, such as bloating, constipation, diarrhea, and abdominal pain. These symptoms are a recognized, non-pelvic manifestation of the disease.
They are often cyclical, intensifying just before or during the menstrual period, linking them to hormonal fluctuations. For some, the nausea and discomfort can become chronic, persisting throughout the entire cycle.
Inflammatory and Hormonal Causes of Nausea
Nausea and vomiting often arise from systemic factors, even when the disease has not directly involved the digestive tract. The misplaced lesions release inflammatory chemicals, notably prostaglandins, which circulate throughout the body. These compounds cause uterine cramping but can also stimulate the vomiting center in the brain, leading to generalized nausea.
The chronic inflammatory state associated with endometriosis contributes to generalized gastrointestinal sensitivity. Systemic inflammation releases chemical mediators, such as cytokines, that irritate the visceral nerves connected to the stomach and intestines. This irritation disrupts normal digestive function and can trigger persistent discomfort.
Hormonal fluctuations throughout the menstrual cycle play an additional role. Prostaglandin levels typically spike just before and during menstruation as estrogen and progesterone levels drop. This surge heightens gut sensitivity and stimulates smooth muscle contractions in the digestive tract, leading to spasms and waves of nausea. Furthermore, the intense pelvic pain (dysmenorrhea) can independently contribute to feelings of nausea and sometimes vomiting.
Bowel Endometriosis and Physical Obstruction
When lesions grow on or penetrate the digestive organs, the mechanism for nausea shifts to a physical obstruction. Deep infiltrating endometriosis (DIE) can affect the bowel wall, most commonly the rectosigmoid colon or the small intestine. Lesions cause pain, cramping, and interfere with peristalsis, the rhythmic muscle contractions necessary for moving food through the digestive tract.
The body’s response involves inflammation, scar tissue, and adhesions, which can tether loops of bowel together. This scarring and infiltration can progressively narrow the internal passage of the intestine, a process called stenosis. Significant narrowing can lead to a partial bowel obstruction, a direct cause of chronic nausea, abdominal distension, and vomiting.
In rare but severe cases, deep infiltrating lesions can cause a high-grade or complete small bowel obstruction. This presents with acute symptoms of abdominal pain, persistent vomiting, and an inability to pass gas. This physical disruption is a distinct and severe cause of gastrointestinal distress, separate from systemic inflammatory effects.
Managing Endometriosis-Related Gastrointestinal Distress
Managing gastrointestinal distress associated with endometriosis begins with accurate symptom tracking to identify the cyclical pattern. A symptom calendar or food diary helps distinguish between endometriosis-related GI issues and other conditions, such as Irritable Bowel Syndrome (IBS), which often co-occurs or is misdiagnosed. Ruling out other digestive disorders, including testing for Small Intestinal Bacterial Overgrowth (SIBO), is an important step.
Medical management includes anti-nausea medications and specific dietary modifications aimed at reducing gut irritation and systemic inflammation. A low-FODMAP diet is often recommended, as it limits fermentable carbohydrates that cause gas and bloating, reducing pressure on sensitive intestines. Hormonal therapies that suppress the growth of lesions also indirectly help by reducing inflammatory prostaglandins.
For severe or unmanageable GI symptoms, especially those caused by physical obstruction or deep infiltration, surgical intervention may be necessary. Excision surgery, performed by a specialist, aims to carefully remove the lesions and associated scar tissue from the bowel wall. In cases of deep bowel involvement, this may require a multidisciplinary surgical team to restore normal intestinal patency and resolve the source of severe nausea and vomiting.