Read your Query.
Trying to explain.
First of All there no condition exist named " fissure in Stomach ".
There may be " ULCER in STOMACH " or " Fissure in Anus " .
Bloody stools with pain during defecation is feature of Fissure in Anus .
Blood in stool
with dark color suggest U probably have " Dysentery
" either amoebic.
Ulcer may cause dark bleed.
You should avoid Wheat ie Bread, Biscuit etc for week.
Also avoid Spicy food & junk food.
Take Oral rehydration solution (ORS) for treatment of Diarrhea .
Also ask for Stool examination & Hemoglobin
check up .
Take Hematenics syrup daily for 1 month
Beet may cause discoloration of stool &
Beet may cause diarrhoea
if not properly washed before eating.
If problem persists, consult Ur nearest Physician.