Brief Answer:
As discussed in details below.

Detailed Answer:
Hi.
Thanks for your query.
Noted the history, Medications, Medical history, shivering with salads and understood your concerns.
Since you have diverticulitis, it may be the reason for pain in left lower abdomen. Constipation should be avoided at any cost as it would cause problems for the diverticulosis and may cause fissure or piles too.
The blood may be due to piles/hemorrhoids or fissure.
If Magnesium alone is not helping, please change over to or have additional another stool softener or laxatives.
If there are frequent bowel movements the probable cause may be:
Overuse/overdose/abuse of magnesium
Or intestinal infection.
Since you have pain too, it is better to get the stool and blood tested as well as Ultrasonography and CT scan to see the status of diverticulosis.
If infection is there a course of an antibiotic active against intestinal as well as urinary tract infection may help you the best.
Constant need to urinate may be due to intestinal infection and thus above tests as mentioned will help further diagnosis and helps in planning a proper management.
Never eat salads as they are causing a trouble/ not suitable for you.
Continue the antibiotic and please let me know the name of the antibiotic that you are prescribed.
Blood may be due to piles or fissure as mentioned above.
I hope this answer helps you, please feel free to ask for further relevant queries if you feel that there is a gap of communication.

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Brief Answer:
Most welcome

Detailed Answer:
Thanks for your appreciation.
Please get the advised things done and a proper diagnosis and a plan for management will be possible.

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