Hi.
The
severe pain in abdomen with
low back pain with the stool you have described can be due to Colitis.
The colon being behind the peritoneal structure -, its inflammation can give associated back-pain.
Colitis can give severe
abdominal pain due to spasms as it tries to push out the contents if it is infected or has some problem not normal to it.
Stool: light brown/yellow lumps with dark brown flacky attachments off them can be due to an infection in the colon, can also be undigested food material.
It can also be due to extreme desquamation of the mucosa due to severe inflammation.
I would advise the following :
Blood- complete blood picture, kidney functions tests, blood sugar fasting and post-lunch,
Urine- routine,microscopy, culture and sensitivity ( before start of antibiotic)
Ultrasonography of abdomen.
Stool test- Routine, microscopy, culture and sensitivity, occult blood, cyst and ova to rule out any worms in the intestines.
Treatment will be an antibiotic suitable for intestines,
metronidazole, Probiotics and antispasmodic depending upon the investigations.