A 33-year-old mother from Merseyside, England, is sharing her story after symptoms she initially believed were caused by constipation were later diagnosed as a rare form of cancer. Chelsea Gallimore hopes her experience will encourage others to seek medical advice if persistent or unusual symptoms do not improve.
Gallimore was diagnosed with a gastrointestinal stromal tumor (GIST), a rare cancer that affects the digestive system and is often detected at a later stage because early symptoms can be limited or absent.
Symptoms
Chelsea Gallimore said she experienced abdominal pain, night sweats, fatigue, and a swollen stomach before receiving her diagnosis.
Believing the symptoms were related to constipation, she was taking medication prescribed by her general practitioner and did not initially think they pointed to a more serious condition.
She later woke with severe abdominal pain and swelling that left her unable to move comfortably for several hours before calling an ambulance.
Diagnosis
After being admitted to the hospital, doctors performed scans that revealed an 8-centimeter mass on her bowel.
A biopsy later confirmed that the mass was a gastrointestinal stromal tumor, commonly known as GIST.
According to Cancer Research UK, GIST is a rare type of sarcoma that develops in the wall of the digestive system. It is most commonly found in the stomach but can also occur elsewhere in the digestive tract.
| Diagnosis Details | Information |
|---|---|
| Patient | Chelsea Gallimore |
| Age at diagnosis | 31 |
| Current age | 33 |
| Cancer type | Gastrointestinal stromal tumor (GIST) |
| Tumor size | 8 centimeters |
Treatment
Chelsea underwent surgery in March 2024 to remove the tumor.
Following surgery, she began treatment with imatinib, a targeted therapy that works by slowing the growth of certain cancer cells.
Doctors stopped the medication in June 2025 after scans suggested the disease remained stable.
However, an emergency CT scan performed on New Year’s Eve later showed the cancer had returned. A follow-up scan several weeks later found that the disease had progressed and spread to other parts of her body.
Doctors informed her that the cancer was now considered incurable and inoperable.
Living
Chelsea is currently receiving treatment aimed at slowing the progression of the disease and extending her life.
She said she experiences ongoing pain, requires strong pain medication, and is receiving support from a palliative care team.
She also undergoes scans every three months so doctors can monitor how well the treatment is working.
Family
Chelsea and her partner, Andrew Mason, have an 11-year-old son named Milo.
Following her diagnosis, the couple decided to move forward with plans to marry in November after discussing their future during a stay in hospice care.
She has also spoken publicly about the emotional impact of discussing end-of-life wishes while still in her early thirties.
Awareness
Chelsea is documenting her experience on social media to raise awareness of GIST and encourage people to pay attention to persistent symptoms.
According to Cancer Research UK, many people with early-stage GIST have few or no symptoms, which can delay diagnosis. When symptoms do occur, they may include abdominal pain, a feeling of fullness, nausea, vomiting, or ongoing fatigue.
Chelsea’s story was also referenced during parliamentary discussions related to the Rare Cancers Act passed in the UK this year.
Her message is not that every case of constipation or bloating signals cancer, but that persistent, worsening, or unexplained symptoms should be evaluated by a healthcare professional.
Chelsea Gallimore’s experience highlights the challenges of diagnosing rare cancers such as GIST, particularly when symptoms resemble common digestive conditions. While most cases of bloating or constipation are not caused by cancer, medical experts advise seeking professional evaluation if symptoms persist, worsen, or are accompanied by other concerning changes. By sharing her journey, Chelsea hopes to increase awareness of a disease that many people have never heard of until they are affected by it.
FAQs
What cancer was Chelsea diagnosed with?
She was diagnosed with a gastrointestinal stromal tumor (GIST).
What symptoms did she first notice?
She experienced bloating, abdominal pain, fatigue, and night sweats.
What is a GIST?
It is a rare cancer that develops in the digestive system.
How is Chelsea being treated now?
She is receiving treatment to slow the cancer’s progression.
What message is Chelsea sharing?
She encourages people to seek medical advice for persistent symptoms.
