Why is abdominal pain present before bowel movement?

Question

Hello doctor,

I have had intermittent pain in my lower left abdomen for seven months now. I had a colonoscopy as soon as the pain started in the summer, but there were no abnormalities seen. There might have been something as the doctor muttered "there is this sort of a thing here" during the colonoscopy, but the doctor who did the colonoscopy would not comment it further because the diagnosis lies in the biopsy samples. The case was dismissed after the biopsies came back normal. However, the pain has continued. I think that it now mostly comes before bowel movements unlike before which was more random, suggesting a colonic cause but I am not sure. I also have soft stools but they could be related to a high-fiber diet.

Attached are some PET-CT pictures were taken five and a half months after the symptoms began. The radiologist claimed that there were no nodular findings seen in the colon, but I can see some mildly elevated nodular activity as well as a possible thickening in the lower left abdomen where the symptoms are. The axial view is mirrored.

Is the structure highlighted a part of the colon wall or a lymph node? What are the black areas that surround the node? Should I opt for another colonoscopy, a needle biopsy or just forget about this?

Answer 1

Hello,

Welcome to icliniq.com.

As I read your question, I just remembered how distressed my sister becomes when she gets similar pains, which enables me to realize your anxieties well. However, her pains have been determined to be of uterine origin.

Please note that, as a radiologist, I always feel confident when I can view the full set of the scan that I am asked to review. However, as you and the reporting radiologist are well convinced about the rest of the imagery, my opinion about the selected images that you've attached (attachment removed to protect patient identity) is as follows:

The black areas represent the gas in your bowels.

About the encircled area: Please note that PET-CT is based on the principle that many pathological lesions accumulated much higher amounts of FDG (fluorodeoxy glucose) than the normal tissue. Because of this basic principle, positive findings on PET are always vividly visible. This is unlike other imaging such as CT, MRI or x-ray where we often have to look for subtle findings.

Look at the urinary bladder where the excreted FDG has accumulated (this is excreted FDG, not a lesion in the bladder). If there were any PET positive lesion in your abdomen, it would show up as bright as the bladder.

Now, look at the area you have encircled. It has some brightness, and although it looks more prominent than the surroundings, its appearance still does not match what we expect a lesion to look like. Please also note that the main image of these types of studies is the axial image, and the others are reconstructed by software. Also, the PET image is superimposed on the CT image by software. Such manipulations often result in the creation of image artifacts. In my opinion, the brightness in the encircled area and its surroundings is artefactual. The mild elevations that you fell you can see are likely due to the folding of the bowel loops.

Yes, there are some lesions that are PET negative. And there are the causes of lower abdominal pain (LAP) that do not create a change in imaging studies. Therefore, your next step should be to discuss with your gastroenterologist about these types of possibilities. Truly, LAP is caused not only by cancers (seen on PET) but also due to vascular, inflammatory, infective and other pathologies, exploring which may lead to the proper diagnosis and appropriate treatment.

I hope this helps.

Why is abdominal pain present before bowel movement?

Ask your health query to a doctor online

Company

Customer Care

Get iCliniq