NHS in England Closed After Initial Enquiries Search on PHSO website

Guy's and St Thomas' NHS Foundation Trust

P-004893 · Statement · Decision date: 24 February 2026 · View Guy's and St Thomas' NHS Foundation Trust scorecard
Diagnosis Diagnosis
Complaint (AI summary)
Ms P complained the Trust failed to identify endometriosis in a 2020 MRI, didn't investigate it properly between 2023, and misdiagnosed IBS.
Outcome (AI summary)
The complaint was closed. The ombudsman found the Trust investigated appropriately, reported the scan correctly, and the IBS diagnosis was appropriate.

Full decision details

The Complaint

6. Ms P complains about the care she received at Guy’s and St Thomas’ NHS Foundation Trust (the Trust) in 2020 and between August 2023 and December 2023.

7. She complains:

• the Trust failed to identify endometriosis present in her MRI in 2020 • the Trust failed to investigate her suspected endometriosis appropriately between August 2023 and December 2023 • the Trust misdiagnosed her with IBS and inappropriately prescribed medication.

8. She says she suffered with painful symptoms of endometriosis without appropriate treatment and her endometriosis developed further. She says the untreated endometriosis caused her to grow tissue in the breast, which caused a cancer scare.

9. She says the misdiagnosis of IBS led to her immune system weakening and being prescribed medication that made her symptoms worse. She said she unnecessarily had a gluten free diet due to the Trust’s advice.

10. As outcomes, she would like an apology from the Trust and a financial remedy.

Background

11. In 2019, Ms P’s GP referred her to the urology clinic at the Trust following her experiencing urological symptoms. The urology clinic requested an MRI bladder scan. The scan report did not mention any possible endometriosis (where cells similar to those in the lining of the womb (uterus) grow in other parts of the body).

12. Ms P had a transvaginal ultrasound (an ultrasound performed internally) at the Trust’s Ovarian Cyst Clinic in August 2023, which identified evidence of adenomyosis (where endometrial tissue grows into the muscular wall of the uterus, leading to symptoms like heavy menstrual bleeding and pelvic pain), and possible endometriosis. The clinic referred Ms P to gynaecology at the Trust for further investigations.

13. In October 2023, a private consultant advised Ms P she likely had adenomyosis, and an endometriosis diagnosis could not be confirmed.

14. Ms P was seen in November 2023 at the Trust, and an MRI was booked in. Following the MRI in December 2023, the Trust identified deep pelvic endometriosis. In December 2023, she was diagnosed with endometriosis and referred to the endometriosis clinic.

15. During this time, Ms P was also under investigations for IBS, and she had an MRI in August 2023 to rule out any other cause. In October 2023, the Trust diagnosed Ms P with IBS and asked her GP to prescribe medication to help alleviate her symptoms, alongside a referral to a dietitian to help with a dietary plan.

Findings

Ms P’s MRI in 2020

21. Before we decide if we should conduct a detailed investigation of a complaint, we look at whether there are signs the organisation has got something wrong. We do this by comparing what should have happened with what did happen. We have done this and have not found any indications that something has gone wrong.

22. Ms P complains she had an MRI scan in 2020 which showed endometriosis, and the Trust failed to report this and make her aware of this diagnosis.

23. Ms P was referred to the urology clinic of the Trust by her GP as she was experiencing urological symptoms after using antibiotics. Urology requested an MRI pelvis and bladder scan to check whether there was urethral diverticulum (a condition where a sac forms on the urethra).

24. The scan report did not mention any possible endometriosis. The Trust sent a letter to her GP in March 2020 with the results of the scan, with no mention of endometriosis. It reported no evidence of urethral diverticulum.

25. In December 2023, when Ms P was undergoing investigations into her suspected endometriosis, the Trust reviewed her previous MRI scan of her bladder and pelvis from 2020, looking for presence of endometriosis. The Trust reported this MRI was consistent with chronic and deep pelvic endometriosis. The Trust performed a new MRI to confirm this diagnosis.

26. Our radiology adviser said the MRI scan was performed to review her bladder and urethra, and though the uterus and ovaries are visible, the scan was not specifically performed to review these areas.

27. They said there was some bowel movement in the imaging, which would make the scan insufficient for diagnosing endometriosis, and they would not expect endometriosis to be diagnosed on the imaging done unless specifically looking for endometriosis.

28. The RCR standards say observations should state the relevant and pertinent findings and allow incidental findings to be mentioned and explained. It says the report should directly answer the clinical question. In line with the RCR standards, the radiologist answered the clinical question asked of them and stated the relevant findings. Our radiology adviser said it was reported correctly and appropriately.

29. We are sorry Ms P has concerns that her endometriosis could have been diagnosed from her scan in 2020. We recognise why she thinks this, as this scan was later reviewed when investigating her endometriosis in 2023.

30. We have seen evidence the scan was reported appropriately and in line with the RCR standards. We have also been advised this scan would not be used in diagnosing endometriosis. We have seen in 2023, the Trust did not rely on this scan and performed new imaging to diagnose endometriosis. As we have not seen indications of a failing, we are declining to investigate this complaint further.

Investigation of Ms P’s suspected diagnosis in 2023

31. Ms P complains about the Trust’s investigation into her endometriosis in 2023. She complains about the delay in diagnosing her endometriosis, and she thinks this could have been diagnosed in August 2023.

32. In August 2023, Ms P had a transvaginal ultrasound at the Ovarian Cyst Clinic at the Trust. The Trust reported evidence of adenomyosis and likely endometriosis. A consultant in the clinic referred Ms P to the gynaecology department for further review.

33. In October 2023, Ms P saw a private endometriosis consultant who said adenomyosis is likely and an endometriosis diagnosis is not confirmed.

34. In November 2023, Ms P had an appointment with gynaecology at the Trust. The Trust recommended an MRI scan of her pelvis, which would identify the presence of endometriosis.

35. In December 2023, Ms P had a pelvic MRI, which confirmed the presence of endometriosis. The Trust referred her to the endometriosis clinic for follow up.

36. In the Trust’s response dated 2 July 2025, it said Ms P was eventually discharged back to her GP due to her lack of engagement with the endometriosis clinic.

37. NICE NG73 1.5 says to offer a transvaginal ultrasound scan to all woman or people with suspected endometriosis. It also says to consider a pelvic MRI scan to diagnosis deep endometriosis and assess its extent.

38. The ESHRE guideline recommends using ultrasound or MRI imaging in the diagnosis of suspected endometriosis.

39. The Trust performed a transvaginal ultrasound, followed by an MRI, where Ms P was diagnosed with deep endometriosis. The Trust followed the diagnostic process recommended by NICE and ESHRE. For deep endometriosis, which Ms P was diagnosed with, it specifically recommends an MRI.

40. Our gynaecology adviser said Ms P’s suspected endometriosis was investigated appropriately, and there was nothing further that should have been done. They also confirmed it was best practice for Ms P to be referred to an endometriosis clinic for further management.

41. We are sorry Ms P felt her endometriosis should have been diagnosed earlier following her transvaginal scan in August 2023. We recognise she was struggling with symptoms of endometriosis.

42. From our consideration, we have seen evidence the Trust investigated Ms P’s suspected endometriosis in line with the NICE and ESHRE guidelines for diagnosing endometriosis. We have not seen evidence the Trust missed an opportunity to diagnose her earlier. Therefore, we will not investigate this complaint further.

Ms P’s IBS diagnosis and treatment

43. Ms P complains the Trust misdiagnosed her with IBS, when her symptoms were related to her endometriosis, and prescribed her medication she did not need.

44. Ms P was reviewed by gastroenterology at the Trust in May 2023 and July 2023. She had been referred to gastroenterology by her GP in October 2022 due to her symptoms of abdominal pain, reduced appetite, and nausea.

45. She reported a history of abdominal pain, bloating, burping, and intermittent constipation and diarrhoea. She said she struggles with eating as it makes her full and she feels unable to digest food properly.

46. The Trust carried out investigations into her symptoms including blood tests, a gastroscopy (a procedure using a camera to check the inside of the upper part of the digestive system), and an MRI scan in August 2023.

47. The Trust reported the blood tests, gastroscopy and MRI scan were normal, and there was no evidence of Crohn’s disease, inflammatory bowel disease or any other pathology.

48. In October 2023, due to her test results being normal, the Trust concluded it is likely she had IBS, which explains her symptoms. It referred her to dieticians for some dietary interventions such as a low FODMAPs diet (FODMAPS are a type of carbohydrate found in a variety of foods that can induce gastrointestinal symptoms). It asked her GP to prescribe Buscopan and Colpermin (peppermint oil), which are medications used to help relieve abdominal pain.

49. In December 2023, Ms P was reviewed by a dietician at the Trust who discussed a plan to help her nutritional intake including a high protein diet. She was discharged in January 2025 as she declined any further treatment from the Trust’s dieticians. Her GP had referred her to a different hospital for further gastrointestinal investigations.

50. NICE CG61 says to consider an assessment for IBS if the person has any of the following symptoms for at least six months:

• abdominal pain or discomfort • bloating • change in bowel habit.

51. It says a diagnosis of IBS should be considered if the person has abdominal pain or discomfort that is either relived by defaecation or associated with altered bowel frequency or stool form, and accompanied by at least 2 of the following symptoms:

• altered stool passage • abdominal bloating, distension, tension or hardness • symptoms made worse by eating • passage of mucus.

52. It says other features such as lethargy, nausea, backache, and bladder symptoms are common with IBS and may be used to support the diagnosis.

53. The BGS guidelines say clinicians should make a positive diagnosis of IBS based on symptoms, in the absence of alarm symptoms or signs and abnormalities on simple blood tests.

54. Ms P had symptoms for over six months, including abdominal pain, bloating, changes in bowel frequency or stool form and nausea. Her blood tests, and other investigations were normal. In line with NICE CG61 and BSG guidelines, Ms P had the associated symptoms and met the criteria for being diagnosed with IBS.

55. Our gastroenterology adviser said both IBS and endometriosis can cause abdominal symptoms, and the symptoms can overlap or present similarly. They said Ms P being diagnosed with endometriosis later in December 2023 does not invalidate her diagnosis of IBS, which met the criteria set out in the NICE and BSG guidelines.

56. NICE CG61 says healthcare professionals should consider prescribing antispasmodic agents for people with IBS. These should be taken as required, alongside dietary, and lifestyle advice.

57. Antispasmodic agents are medications to relieve spasms, cramps and related pain. These include buscopan and peppermint oil. The Trust prescribed Ms P these medications in October 2023, in line with NICE CG61.

58. The BGS guideline recommended a low FODMAP diet as treatment for IBS. In October 2023, this was suggested as a potential intervention for her when she was referred to dieticians at the Trust. Although this was not formally recommended by the Trust, it is a recommended diet in line with guidelines.

59. Our gastroenterology adviser said a low FODMAP diet is a well recognised diet in managing IBS, and the antispasmodic medications is commonly prescribed for managing symptoms of IBS. They said the Trust proposed an appropriate treatment plan for Ms P’s IBS.

60. We are sorry Ms P disagrees with her diagnosis of IBS, and we recognise her being diagnosed with endometriosis later on has contributed to this concern due to the similar symptoms.

61. We have seen evidence the Trust followed NICE CG61 and the BSG guidelines when it diagnosed her with IBS. We have not seen any indications of a failing by the Trust in how it reached Ms P’s diagnosis. We have also seen the medication it prescribed was in line with guidelines. As we have not seen any indications of failings, we are declining to investigate this complaint further.

62. We are sorry Ms P is unhappy with the care she received from the Trust in relation to her diagnosis of endometriosis and IBS. We understand this must have been a stressful time for Ms P due to her ongoing symptoms. We are satisfied Ms P’s symptoms were investigated and treated in accordance with the above guidelines. We have also not seen evidence the Trust failed to diagnose Ms P with endometriosis in 2020. As we have not seen indications of failings in Ms P’s complaint, we are declining to investigate it any further. We are sorry for any disappointment our decision may cause Ms P.

Our Decision

1. We have carefully considered Ms P’s complaint about Guy’s and St Thomas’ NHS Foundation Trust (the Trust). We are sorry to hear how she has suffered with endometriosis for many years, and we recognise how upsetting it was for Ms P to find out her endometriosis was present in a scan performed by the Trust in 2020. We understand this has been a distressing time for Ms P.

2. Ms P says the Trust failed to investigate her endometriosis appropriately between November 2023 and December 2023, which led to her endometriosis developing further without treatment. We are sorry Ms P felt there was a delay by the Trust to diagnose her endometriosis. We have seen evidence the Trust investigated Ms P’s suspected endometriosis appropriately.

3. Ms P also says the Trust failed to report her endometriosis that was present in a scan she had at the Trust in 2020. We understand why Ms P is upset this was not identified in 2020. From our consideration, we think the Trust reported Ms P’s scan appropriately.

4. Ms P says the Trust inappropriately diagnosed her with irritable bowel syndrome (IBS), when her symptoms were actually due to her endometriosis. We have not seen evidence Ms P was diagnosed inappropriately, and we think the Trust’s assessment of Ms P was appropriate.

5. As we have not identified any indications of failings in the care provided by the Trust, we will not be investigating this complaint any further. We are sorry for any distress that this may cause Ms P.

Other Decisions About Guy's and St Thomas' NHS Foundation Trust

P-004974 · 4 Mar 2026
Mr A complains about the care his son, C, received from the Trust in 2023. He says the Trust failed …
Closed After Initial Enquiries
P-004749 · 30 Jan 2026
Mr A complains about the care provided to his wife, Mrs B, by Guy’s and St Thomas’ NHS Foundation Trust …
Not Upheld
P-004753 · 30 Jan 2026
An NHS Trust discharged a patient before they were medically fit, failed to carry out an occupational health assessment, did …
Closed After Initial Enquiries
P-004706 · 28 Jan 2026
Miss U complains about the care and treatment her mother received at a Trust.
Closed After Initial Enquiries
P-004608 · 13 Jan 2026
Mrs S is complaining that she should have received laser treatment.
Closed After Initial Enquiries
View all decisions for this organisation →